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  • SQLAuthority News – History of the Database – 5 Years of Blogging at SQLAuthority

    - by pinaldave
    Don’t miss the Contest:Participate in 5th Anniversary Contest   Today is this blog’s birthday, and I want to do a fun, informative blog post. Five years ago this day I started this blog. Intention – my personal web blog. I wrote this blog for me and still today whatever I learn I share here. I don’t want to wander too far off topic, though, so I will write about two of my favorite things – history and databases.  And what better way to cover these two topics than to talk about the history of databases. If you want to be technical, databases as we know them today only date back to the late 1960’s and early 1970’s, when computers began to keep records and store memories.  But the idea of memory storage didn’t just appear 40 years ago – there was a history behind wanting to keep these records. In fact, the written word originated as a way to keep records – ancient man didn’t decide they suddenly wanted to read novels, they needed a way to keep track of the harvest, of their flocks, and of the tributes paid to the local lord.  And that is how writing and the database began.  You could consider the cave paintings from 17,0000 years ago at Lascaux, France, or the clay token from the ancient Sumerians in 8,000 BC to be the first instances of record keeping – and thus databases. If you prefer, you can consider the advent of written language to be the first database.  Many historians believe the first written language appeared in the 37th century BC, with Egyptian hieroglyphics. The ancient Sumerians, not to be outdone, also created their own written language within a few hundred years. Databases could be more closely described as collections of information, in which case the Sumerians win the prize for the first archive.  A collection of 20,000 stone tablets was unearthed in 1964 near the modern day city Tell Mardikh, in Syria.  This ancient database is from 2,500 BC, and appears to be a sort of law library where apprentice-scribes copied important documents.  Further archaeological digs hope to uncover the palace library, and thus an even larger database. Of course, the most famous ancient database would have to be the Royal Library of Alexandria, the great collection of records and wisdom in ancient Egypt.  It was created by Ptolemy I, and existed from 300 BC through 30 AD, when Julius Caesar effectively erased the hard drives when he accidentally set fire to it.  As any programmer knows who has forgotten to hit “save” or has experienced a sudden power outage, thousands of hours of work was lost in a single instant. Databases existed in very similar conditions up until recently.  Cuneiform tablets gave way to papyrus, which led to vellum, and eventually modern paper and the printing press.  Someday the databases we rely on so much today will become another chapter in the history of record keeping.  Who knows what the databases of tomorrow will look like! Reference:  Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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  • It's like I'm in recovery mode after update, but I'm not

    - by mawburn
    I used the Ubuntu software updater and updated to the most recent packages. After the last update today, it's like I have gone into recovery mode, but I haven't. I am running UbuntuGNOME First, everything looks like this: Switching to dark mode does nothing. Also, default applications do not work. Such as Startup and the default screenshot application. Everything was working fine before the latest software update. System Info Ubuntu 14.04 LTS Gnome-Shell 3.10.4 Kernel 3.13.0-29 I can't figure out how to get an update history, but this is almost a fresh install. It's about a week old install and this is the 3rd time I've used the Ubuntu Software Update. I am running AMD ATI HD6700 with the proprietary Catalyst drivers. I tried to provide all information that I thought would be useful, if you need any more please let me know. Edit - I believe something went wrong within these updates: Update Log: Start-Date: 2014-06-09 19:07:07 Commandline: aptdaemon role='role-commit-packages' sender=':1.68' Install: libgnome-desktop-3-10:amd64 (3.12.0-0~eugenesan~trusty2) Upgrade: gnome-session-common:amd64 (3.9.90-0ubuntu12, 3.12.0-0~eugenesan~trusty10), gnome-session-bin:amd64 (3.9.90-0ubuntu12, 3.12.0-0~eugenesan~trusty10), gir1.2-gnomedesktop-3.0:amd64 (3.8.4-0ubuntu3, 3.12.0-0~eugenesan~trusty2), gnome-session:amd64 (3.9.90-0ubuntu12, 3.12.0-0~eugenesan~trusty10), python-libxml2:amd64 (2.9.1+dfsg1-3ubuntu4.1, 2.9.1+dfsg1-3ubuntu4.2), libspice-server1:amd64 (0.12.4-0nocelt2, 0.12.4-0nocelt2.02~eugenesan~trusty1), gir1.2-mutter-3.0:amd64 (3.10.4-0ubuntu2, 3.10.4-0ubuntu2.1), xserver-xorg-video-qxl:amd64 (0.1.1-0ubuntu3, 0.1.1-0ubuntu3.01), libxml2:amd64 (2.9.1+dfsg1-3ubuntu4.1, 2.9.1+dfsg1-3ubuntu4.2), libxml2:i386 (2.9.1+dfsg1-3ubuntu4.1, 2.9.1+dfsg1-3ubuntu4.2), gnome-desktop3-data:amd64 (3.8.4-0ubuntu3, 3.12.0-0~eugenesan~trusty2), mutter:amd64 (3.10.4-0ubuntu2, 3.10.4-0ubuntu2.1), mutter-common:amd64 (3.10.4-0ubuntu2, 3.10.4-0ubuntu2.1), libxml2-utils:amd64 (2.9.1+dfsg1-3ubuntu4.1, 2.9.1+dfsg1-3ubuntu4.2), libmutter0c:amd64 (3.10.4-0ubuntu2, 3.10.4-0ubuntu2.1) End-Date: 2014-06-09 19:07:12 I also installed Citrix Receiver today, following the tutorial here: Citrix Receiver 12.1 on Ubuntu 14.04 64-bit Log Start-Date: 2014-06-09 18:59:06 Commandline: apt-get install libmotif4:i386 nspluginwrapper lib32z1 libc6-i386 libxp6:i386 libxpm4:i386 libasound2:i386 Install: libmotif-common:amd64 (2.3.4-5, automatic), libatk1.0-0:i386 (2.10.0-2ubuntu2, automatic), libxft2:i386 (2.3.1-2, automatic), libgraphite2-3:i386 (1.2.4-1ubuntu1, automatic), nspluginviewer:i386 (1.4.4-0ubuntu5, automatic), libpango-1.0-0:i386 (1.36.3-1ubuntu1, automatic), libxcursor1:i386 (1.1.14-1, automatic), libmotif4:i386 (2.3.4-5), libxm4:amd64 (2.3.4-5, automatic), libxm4:i386 (2.3.4-5, automatic), libxp6:i386 (1.0.2-1ubuntu1), libpangocairo-1.0-0:i386 (1.36.3-1ubuntu1, automatic), libxcb-render0:i386 (1.10-2ubuntu1, automatic), libthai0:i386 (0.1.20-3, automatic), libharfbuzz0b:i386 (0.9.27-1, automatic), libpixman-1-0:i386 (0.30.2-2ubuntu1, automatic), libpangoft2-1.0-0:i386 (1.36.3-1ubuntu1, automatic), libcairo2:i386 (1.13.0~20140204-0ubuntu1, automatic), lib32z1:amd64 (1.2.8.dfsg-1ubuntu1), libjasper1:i386 (1.900.1-14ubuntu3, automatic), libgtk2.0-0:i386 (2.24.23-0ubuntu1.1, automatic), nspluginwrapper:amd64 (1.4.4-0ubuntu5), libuil4:amd64 (2.3.4-5, automatic), libuil4:i386 (2.3.4-5, automatic), libxcb-shm0:i386 (1.10-2ubuntu1, automatic), libxmu6:i386 (1.1.1-1, automatic), libc6-i386:amd64 (2.19-0ubuntu6), libxinerama1:i386 (1.1.3-1, automatic), libgdk-pixbuf2.0-0:i386 (2.30.7-0ubuntu1, automatic), libxcomposite1:i386 (0.4.4-1, automatic), libmrm4:amd64 (2.3.4-5, automatic), libmrm4:i386 (2.3.4-5, automatic), libdatrie1:i386 (0.2.8-1, automatic), libxrandr2:i386 (1.4.2-1, automatic), libxpm4:i386 (3.5.10-1) End-Date: 2014-06-09 18:59:11

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  • New R Interface to Oracle Data Mining Available for Download

    - by charlie.berger
      The R Interface to Oracle Data Mining ( R-ODM) allows R users to access the power of Oracle Data Mining's in-database functions using the familiar R syntax. R-ODM provides a powerful environment for prototyping data analysis and data mining methodologies. R-ODM is especially useful for: Quick prototyping of vertical or domain-based applications where the Oracle Database supports the application Scripting of "production" data mining methodologies Customizing graphics of ODM data mining results (examples: classification, regression, anomaly detection) The R-ODM interface allows R users to mine data using Oracle Data Mining from the R programming environment. It consists of a set of function wrappers written in source R language that pass data and parameters from the R environment to the Oracle RDBMS enterprise edition as standard user PL/SQL queries via an ODBC interface. The R-ODM interface code is a thin layer of logic and SQL that calls through an ODBC interface. R-ODM does not use or expose any Oracle product code as it is completely an external interface and not part of any Oracle product. R-ODM is similar to the example scripts (e.g., the PL/SQL demo code) that illustrates the use of Oracle Data Mining, for example, how to create Data Mining models, pass arguments, retrieve results etc. R-ODM is packaged as a standard R source package and is distributed freely as part of the R environment's Comprehensive R Archive Network (CRAN). For information about the R environment, R packages and CRAN, see www.r-project.org. R-ODM is particularly intended for data analysts and statisticians familiar with R but not necessarily familiar with the Oracle database environment or PL/SQL. It is a convenient environment to rapidly experiment and prototype Data Mining models and applications. Data Mining models prototyped in the R environment can easily be deployed in their final form in the database environment, just like any other standard Oracle Data Mining model. What is R? R is a system for statistical computation and graphics. It consists of a language plus a run-time environment with graphics, a debugger, access to certain system functions, and the ability to run programs stored in script files. The design of R has been heavily influenced by two existing languages: Becker, Chambers & Wilks' S and Sussman's Scheme. Whereas the resulting language is very similar in appearance to S, the underlying implementation and semantics are derived from Scheme. R was initially written by Ross Ihaka and Robert Gentleman at the Department of Statistics of the University of Auckland in Auckland, New Zealand. Since mid-1997 there has been a core group (the "R Core Team") who can modify the R source code archive. Besides this core group many R users have contributed application code as represented in the near 1,500 publicly-available packages in the CRAN archive (which has shown exponential growth since 2001; R News Volume 8/2, October 2008). Today the R community is a vibrant and growing group of dozens of thousands of users worldwide. It is free software distributed under a GNU-style copyleft, and an official part of the GNU project ("GNU S"). Resources: R website / CRAN R-ODM

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  • Sprinkle Some Magik on that Java Virtual Machine

    - by Jim Connors
    GE Energy, through its Smallworld subsidiary, has been providing geospatial software solutions to the utility and telco markets for over 20 years.  One of the fundamental building blocks of their technology is a dynamically-typed object oriented programming language called Magik.  Like Java, Magik source code is compiled down to bytecodes that run on a virtual machine -- in this case the Magik Virtual Machine. Throughout the years, GE has invested considerable engineering talent in the support and maintenance of this virtual machine.  At the same time vast energy and resources have been invested in the Java Virtual Machine. The question for GE has been whether to continue to make that investment on its own or to leverage massive effort provided by the Java community? Utilizing the Java Virtual Machine instead of maintaining its own virtual machine would give GE more opportunity to focus on application solutions.   At last count, there are dozens, perhaps hundreds of examples of programming languages that have been hosted atop the Java Virtual Machine.  Prior to the release of Java 7, that effort, although certainly possible, was generally less than optimal for languages like Magik because of its dynamic nature.  Java, as a statically typed language had little use for this capability.  In the quest to be a more universal virtual machine, Java 7, via JSR-292, introduced a new bytecode called invokedynamic.  In short, invokedynamic affords a more flexible method call mechanism needed by dynamic languages like Magik. With this new capability GE Energy has succeeded in hosting their Magik environment on top of the Java Virtual Machine.  So you may ask, why would GE wish to do such a thing?  The benefits are many: Competitors to GE Energy claimed that the Magik environment was proprietary.  By utilizing the Java Virtual Machine, that argument gets put to bed.  JVM development is done in open source, where contributions are made world-wide by all types of organizations and individuals. The unprecedented wealth of class libraries and applications written for the Java platform are now opened up to Magik/JVM platform as first class citizens. In addition, the Magik/JVM solution vastly increases the developer pool to include the 9 million Java developers -- the largest developer community on the planet. Applications running on the JVM showed substantial performance gains, in some cases as much as a 5x speed up over the original Magik platform. Legacy Magik applications can still run on the original platform.  They can be seamlessly migrated to run on the JVM by simply recompiling the source code. GE can now leverage the huge Java community.  Undeniably the best virtual machine ever created, hundreds if not thousands of world class developers continually improve, poke, prod and scrutinize all aspects of the Java platform.  As enhancements are made, GE automatically gains access to these. As Magik has little in the way of support for multi-threading, GE will benefit from current and future Java offerings (e.g. lambda expressions) that aim to further facilitate multi-core/multi-threaded application development. As the JVM is available for many more platforms, it broadens the reach of Magik, including the potential to run on a class devices never envisioned just a few short years ago.  For example, Java SE compatible runtime environments are available for popular embedded ARM/Intel/PowerPC configurations that could theoretically host this software too. As compared to other JVM language projects, the Magik integration differs in that it represents a serious commercial entity betting a sizable part of its business on the success of this effort.  Expect to see announcements not only from General Electric, but other organizations as they realize the benefits of utilizing the Java Virtual Machine.

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  • How views are changing in future versions of SQL

    - by Rob Farley
    April is here, and this weekend, SQL v11.0 (previous known as Denali, now known as SQL Server 2012) reaches general availability. And so I thought I’d share some news about what’s coming next. I didn’t hear this at the MVP Summit earlier this year (where there was lots of NDA information given, but I didn’t go), so I think I’m free to share it. I’ve written before about CTEs being query-scoped views. Well, the actual story goes a bit further, and will continue to develop in future versions. A CTE is a like a “temporary temporary view”, scoped to a single query. Due to globally-scoped temporary objects using a two-hashes naming style, and session-scoped (or ‘local’) temporary objects a one-hash naming style, this query-scoped temporary object uses a cunning zero-hash naming style. We see this implied in Books Online in the CREATE TABLE page, but as we know, temporary views are not yet supported in the SQL Server. However, in a breakaway from ANSI-SQL, Microsoft is moving towards consistency with their naming. We know that a CTE is a “common table expression” – this is proving to be a more strategic than you may have appreciated. Within the Microsoft product group, the term “Table Expression” is far more widely used than just CTEs. Anything that can be used in a FROM clause is referred to as a Table Expression, so long as it doesn’t actually store data (which would make it a Table, rather than a Table Expression). You can see this is not just restricted to the product group by doing an internet search for how the term is used without ‘common’. In the past, Books Online has referred to a view as a “virtual table” (but notice that there is no SQL 2012 version of this page). However, it was generally decided that “virtual table” was a poor name because it wasn’t completely accurate, and it’s typically accepted that virtualisation and SQL is frowned upon. That page I linked to says “or stored query”, which is slightly better, but when the SQL 2012 version of that page is actually published, the line will be changed to read: “A view is a stored table expression (STE)”. This change will be the first of many. During the SQL 2012 R2 release, the keyword VIEW will become deprecated (this will be SQL v11 SP1.5). Three versions later, in SQL 14.5, you will need to be in compatibility mode 140 to allow “CREATE VIEW” to work. Also consistent with Microsoft’s deprecation policy, the execution of any query that refers to an object created as a view (rather than the new “CREATE STE”), will cause a Deprecation Event to fire. This will all be in preparation for the introduction of Single-Column Table Expressions (to be introduced in SQL 17.3 SP6) which will finally shut up those people waiting for a decent implementation of Inline Scalar Functions. And of course, CTEs are “Common” because the Table Expression definition needs to be repeated over and over throughout a stored procedure. ...or so I think I heard at some point. Oh, and congratulations to all the new MVPs on this April 1st. @rob_farley

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  • Future Of F# At Jazoon 2011

    - by Alois Kraus
    I was at the Jazoon 2011 in Zurich (Switzerland). It was a really cool event and it had many top notch speaker not only from the Microsoft universe. One of the most interesting talks was from Don Syme with the title: F# Today/F# Tomorrow. He did show how to use F# scripting to browse through open databases/, OData Web Services, Sharepoint, …interactively. It looked really easy with the help of F# Type Providers which is the next big language feature in a future F# version. The object returned by a Type Provider is used to access the data like in usual strongly typed object model. No guessing how the property of an object is called. Intellisense will show it just as you expect. There exists a range of Type Providers for various data sources where the schema of the stored data can somehow be dynamically extracted. Lets use e.g. a free database it would be then let data = DbProvider(http://.....); data the object which contains all data from e.g. a chemical database. It has an elements collection which contains an element which has the properties: Name, AtomicMass, Picture, …. You can browse the object returned by the Type Provider with full Intellisense because the returned object is strongly typed which makes this happen. The same can be achieved of course with code generators that use an input the schema of the input data (OData Web Service, database, Sharepoint, JSON serialized data, …) and spit out the necessary strongly typed objects as an assembly. This does work but has the downside that if the schema of your data source is huge you will quickly run against a wall with traditional code generators since the generated “deserialization” assembly could easily become several hundred MB. *** The following part contains guessing how this exactly work by asking Don two questions **** Q: Can I use Type Providers within C#? D: No. Q: F# is after all a library. I can reference the F# assemblies and use the contained Type Providers? D: F# does annotate the generated types in a special way at runtime which is not a static type that C# could use. The F# type providers seem to use a hybrid approach. At compilation time the Type Provider is instantiated with the url of your input data. The obtained schema information is used by the compiler to generate static types as usual but only for a small subset (the top level classes up to certain nesting level would make sense to me). To make this work you need to access the actual data source at compile time which could be a problem if you want to keep the actual url in a config file. Ok so this explains why it does work at all. But in the demo we did see full intellisense support down to the deepest object level. It looks like if you navigate deeper into the object hierarchy the type provider is instantiated in the background and attach to a true static type the properties determined at run time while you were typing. So this type is not really static at all. It is static if you define as a static type that its properties shows up in intellisense. But since this type information is determined while you are typing and it is not used to generate a true static type and you cannot use these “intellistatic” types from C#. Nonetheless this is a very cool language feature. With the plotting libraries you can generate expressive charts from any datasource within seconds to get quickly an overview of any structured data storage. My favorite programming language C# will not get such features in the near future there is hope. If you restrict yourself to OData sources you can use LINQPad to query any OData enabled data source with LINQ with ease. There you can query Stackoverflow with The output is also nicely rendered which makes it a very good tool to explore OData sources today.

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  • Why don't we just fix Javascript?

    - by Jan Meyer
    Javascript sucks because of a few fatalities well pointed out by Douglas Crockford. We talk a lot about it. But the point here is, why we don't fix it? Coffeescript of course does that and a lot more. But the question here is another: if we provide a webservice that can convert one version of Javascript to the next, and so on, we can keep the language up to date. Such a conversion allows old code to run, albeit with an ever-increasing startup delay, as newer browsers convert old code to the new syntax. To avoid that delay, the site only needs to take the output of the code-transform and paste it in! The effort has immediate benefits for those businesses interested in the results. The rest can sleep tight: their code will continue to run. If we provide backward code-transformation also, then elder browsers can also run ANY new code! Migration scripts should be created by those that make changes to a language. Today they don't, which is in itself a fundamental omission! It should be am obvious part of their job to provide them, as their job isn't really done without them. The onus of making it work should be on them. With this system Any site will be able to run in Any browser, but new code will run best on the newest browsers. This way we reap the benefit of an up-to-date and productive development environment, where today we suffer, supposedly because of yesterday. This is a misconception. We are all trapped in committee-thinking, and we drag along things that only worsen our performance over time! We cause an ever increasing complexity that is hard to underestimate. Javascript is easily fixed. The fact is we don't. As an example, I have seen Patrick Michaud tackle the migration problem in PmWiki. It included forward migration scripts. Whenever syntax changes were made, a migration script was added to transform pages to the new syntax. As far as I know, ALL migrations have worked flawlessly. In other words, we don't tackle the migration problem, we just drag it along. We are incompetent! And why is that? Because technically incompetent people feel they must decide for us. Because they are incompetent, fear rules them. They are obnoxiously conservative, and we suffer the consequence of bad leadership. But the competent don't need to play by the same rules. They can (and must) change them. They are the path forward. It is about time to leave the past behind, and pursue the leanest meanest, no, eternal functionality. That would in and of itself revolutionize programming. So, why don't we stop whining and fix programming? Begin with Javascript and change the world. Even if the browser doesn't hook into this system, coders could. So language updaters should take it upon them to provide migration scripts. Once they exist, browsers may take advantage of them.

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  • DATEFROMPARTS

    - by jamiet
    I recently overheard a remark by Greg Low in which he said something akin to "the most interesting parts of a new SQL Server release are the myriad of small things that are in there that make a developer's life easier" (I'm paraphrasing because I can't remember the actual quote but it was something like that). The new DATEFROMPARTS function is a classic example of that . It simply takes three integer parameters and builds a date out of them (if you have used DateSerial in Reporting Services then you'll understand). Take the following code which generates the first and last day of some given years: SELECT 2008 AS Yr INTO #Years UNION ALL SELECT 2009 UNION ALL SELECT 2010 UNION ALL SELECT 2011 UNION ALL SELECT 2012SELECT [FirstDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 101))),      [LastDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 1231)))FROM   #Years y here are the results: That code is pretty gnarly though with those CONVERTs in there and, worse, if the character string is constructed in a certain way then it could fail due to localisation, check this out: SET LANGUAGE french;SELECT dt,Month_Name=DATENAME(mm,dt)FROM   (       SELECT  dt = CONVERT(DATETIME,CONVERT(CHAR(4),y.[Yr]) + N'-01-02')       FROM    #Years y       )d;SET LANGUAGE us_english;SELECT dt,Month_Name=DATENAME(mm,dt)FROM   (       SELECT  dt = CONVERT(DATETIME,CONVERT(CHAR(4),y.[Yr]) + N'-01-02')       FROM    #Years y       )d; Notice how the datetime has been converted differently based on the language setting. When French, the string "2012-01-02" gets interpreted as 1st February whereas when us_english the same string is interpreted as 2nd January. Instead of all this CONVERTing nastiness we have DATEFROMPARTS: SELECT [FirstDayOfYear] = DATEFROMPARTS(y.[Yr],1,1),    [LasttDayOfYear] = DATEFROMPARTS(y.[Yr],12,31)FROM   #Years y How much nicer is that? The bad news of course is that you have to upgrade to SQL Server 2012 or migrate to SQL Azure if you want to use it, as is the way of the world! Don't forget that if you want to try this code out on SQL Azure right this second, for free, you can do so by connecting up to AdventureWorks On Azure. You don't even need to have SSMS handy - a browser that runs Silverlight will do just fine. Simply head to https://mhknbn2kdz.database.windows.net/ and use the following credentials: Database AdventureWorks2012 User sqlfamily Password sqlf@m1ly One caveat, SELECT INTO doesn't work on SQL Azure so you'll have to use this instead: DECLARE @y TABLE ( [Yr] INT);INSERT @y([Yr])SELECT 2008 AS Yr UNION ALL SELECT 2009 UNION ALL SELECT 2010 UNION ALL SELECT 2011 UNION ALL SELECT 2012;SELECT [FirstDayOfYear] = DATEFROMPARTS(y.[Yr],1,1),      [LastDayOfYear] = DATEFROMPARTS(y.[Yr],12,31)FROM @y y;SELECT [FirstDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 101))),      [LastDayOfYear] = CONVERT(DATE,CONVERT(CHAR(8),((y.[Yr] * 10000) + 1231)))FROM @y y; @Jamiet

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  • Fun with Python

    - by dotneteer
    I am taking a class on Coursera recently. My formal education is in physics. Although I have been working as a developer for over 18 years and have learnt a lot of programming on the job, I still would like to gain some systematic knowledge in computer science. Coursera courses taught by Standard professors provided me a wonderful chance. The three languages recommended for assignments are Java, C and Python. I am fluent in Java and have done some projects using C++/MFC/ATL in the past, but I would like to try something different this time. I first started with pure C. Soon I discover that I have to write a lot of code outside the question that I try to solve because the very limited C standard library. For example, to read a list of values from a file, I have to read characters by characters until I hit a delimiter. If I need a list that can grow, I have to create a data structure myself, something that I have taking for granted in .Net or Java. Out of frustration, I switched to Python. I was pleasantly surprised to find that Python is very easy to learn. The tutorial on the official Python site has the exactly the right pace for me, someone with experience in another programming. After a couple of hours on the tutorial and a few more minutes of toying with IDEL, I was in business. I like the “battery supplied” philosophy that gives everything that I need out of box. For someone from C# or Java background, curly braces are replaced by colon(:) and tab spaces. Although I tend to miss colon from time to time, I found that the idea of tab space is actually very nice once I get use to them. I also like to feature of multiple assignment and multiple return parameters. When I need to return a by-product, I just add it to the list of returns. When would use Python? I would use Python if I need to computer anything quick. The language is very easy to use. Python has a good collection of libraries (packages). The REPL of the interpreter allows me test ideas quickly before committing them into script. Lots of computer science work have been ported from Lisp to Python. Some universities are even teaching SICP in Python. When wouldn’t I use Python? I mostly would not use it in a managed environment, such as Ironpython or Jython. Both .Net and Java already have a rich library so one has to make a choice which library to use. If we use the managed runtime library, the code will tie to the particular runtime and thus not portable. If we use the Python library, then we will face the relatively long start-up time. For this reason, I would not recommend to use Ironpython for WP7 development. The only situation that I see merit with managed Python is in a server application where I can preload Python so that the start-up time is not a concern. Using Python as a managed glue language is an over-kill most of the time. A managed Scheme could be a better glue language as it is small enough to start-up very fast.

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  • Construction Paper, Legos, and Architectural Modeling

    I can remember as a kid playing with construction paper and Legos to explore my imagination. Through my exploration I was able to build airplanes, footballs, guns, and more, out of paper. Additionally I could create entire cities, robots, or anything else I could image out of Legos.  These toys, I now realize were in fact tools that gave me an opportunity to explore my ideas in the physical world through the use of modeling.  My imagination was allowed to run wild as I, unknowingly at the time, made design decisions that directly affected the models I was building from the raw materials.  To prove my point further, I can remember building a paper airplane that seemed to go nowhere when I tried to throw it. So I decided to attach a paper clip to the plane before I decided to throw it the next time to test my concept that by adding more weight to the plane that it would fly better and for longer distances. The paper airplane allowed me to model my design decision through the use of creating an artifact in that I created a paper airplane that was carrying extra weight through the incorporation of the paper clip in to the design. Also, I remember using Legos to build all sorts of creations, and these creations became artifacts of my imagination. As I further and further defined my Lego creations through the process of playing I was able to create elaborate artifacts of my imagination. These artifacts represented design decision I had made in the evolution of my creation through my child like design process. In some form or fashion the artifacts I created as a kid are very similar to the artifacts that I create when I model a software architectural concept or a software design in that the process of making decisions is directly translated in to a tangible model in the form of an architectural model. Architectural models have been defined as artifacts that depict design decisions of a system’s architecture.  The act of creating architectural models is the act of architectural modeling. Furthermore, architectural modeling is the process of creating a physical model based architectural concepts and documenting these design decisions. In the process of creating models, the standard notation used is Architectural modeling notation. This notation is the primary method of capturing the essence of design decisions regarding architecture.  Modeling notations can vary based on the need and intent of a project; typically they range from natural language to a diagram based notation. Currently, Unified Markup Language (UML) is the industry standard in terms of architectural modeling notation  because allows for architectures to be defined through a series of boxes, lines, arrows and other basic symbols that encapsulate design designs in to virtual components, connectors, configurations and interfaces.  Furthermore UML allows for additional break down of models through the use of natural language as to explain each section of the model in plain English. One of the major factors in architectural modeling is to define what is to be modeled. As a basic rule of thumb, I tend to model architecture based on the complexity of systems or sub sub-systems of architecture. Another key factor is the level of detail that is actually needed for a model. For example if I am modeling a system for a CEO to view then the low level details will be omitted. In comparison, if I was modeling a system for another engineer to actually implement I would include as much detailed information as I could to help the engineer implement my design.

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  • [EF + ORACLE] Updating and Deleting Entities

    - by JTorrecilla
    Prologue In previous chapters we have seen how to insert data through EF, with and without sequences. In this one, we are going to see how to Update and delete Data from the DB. Updating data The update of the Entity Data (properties) is a very common and easy action. Before of change any of the properties of the Entity, we can check the EntityState property, and we can see that is EntityState.Unchanged.   For making an update it is needed to get the Entity which will be modified. In the following example, I use the GetEmployeeByNumber to get a valid Entity: 1: EMPLEADOS emp=GetEmployeeByNumber(2); 2: emp.Name="a"; 3: emp.Phone="2"; 4: emp.Mail="aa"; After modifying the desired properties of the Entity, we are going to check again Entitystate property, which now has the EntityState.Modified value. To persist the changes to the DB is necessary to invoke the SaveChanges function of our context. 1: context.SaveChanges(); After modifying the desired properties of the Entity, we are going to check again Entitystate property, which now has the EntityState.Modified value. To persist the changes to the DB is necessary to invoke the SaveChanges function of our context. If we check again the EntityState property we will see that the value will be EntityState.Unchanged.   Deleting Data Another easy action is to delete an Entity.   The first step to delete an Entity from the DB is to select the entity: 1: CLIENTS selectedClient = GetClientByNumber(15); 2: context.CLIENTES.DeleteObject(clienteSeleccionado); Before invoking the DeleteObject function, we will check EntityStet which value must be EntityState.Unchanged. After deleting the object, the state will be changed to EntitySate.Deleted. To commit the action we have to invoke the SaveChanges function. Aftar that, the EntityState property will be EntityState.Detached. Cascade Entity Framework lets cascade updates and deletes, although I never see cascade updates. What is a cascade delete? A cascade delete is an action that allows to delete all the related object to the object we desire to delete. This option could be established in the DB manager, or it could be in the EF model designer. For example: With a given relation (1-N) between clients and requests. The common situation must be to let delete those clients whose have no requests. If we select the relation between both entities, and press the second mouse button, we can see the properties panel of the relation. The props are: This grid shows the relations indicating the Master table(Clients) and the end point (Cabecera or Requests) The property “End 1 OnDelete” indicates the action to do when a Entity from the Master will be deleted. There are two options: - None: No action will be done, it is said, if a Entity has details entities it could not be deleted. - Cascade: It will delete all related entities to the master Entity. If we enable the cascade delete in a relation, and we invoke the DeleteObject function of the set, we could observe that all the related object indicates a Entitystate.Deleted state. Like an update, insert or common delete, until we commit the changes with SaveChanges function, the data would not be commited. Si habilitamos el borrado en cascada de una relación, e invocamos a la función DeleteObject del conjunto, podremos observar que todas las entidades de Detalle (de la relación indicada) presentan el valor EntityState.Deleted en la propiedad EntityState. Del mismo modo que en el borrado, inserción o actualización, hasta que no se invoque al método SaveChanges, los cambios no van a ser confirmados en la Base de Datos. Finally In this chapter we have seen how to update a Entity, how to delete an Entity and how to implement Cascade Deleting through EF. In next chapters we will see how to query the DB data.

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  • How can a developer realize the full value of his work [closed]

    - by Jubbat
    I, honestly, don't want to work as a developer in a company anymore after all I have seen. I want to continue developing software, yes, but not in the way I see it all around me. And I'm in London, a city that congregates lots of great developers from the whole world, so it shouldn't be a problem of location. So, what are my concerns? First of all, best case scenario: you are paying managers salary out of yours. You are consistently underpaid by making up for the average manager negative net return plus his whole salary. Typical scenario. I am a reasonably good developer with common sense who cares for readable code with attention to basic principles. I have found way too often, overconfident and arrogant developers with a severe lack of common sense. Personally, I don't want to follow TDD or Agile practices like all the cool kids nowadays. I would read about them, form my own opinion and take what I feel is useful, but don't follow it sheepishly. I want to work with people who understand that you have to design good interfaces, you absolutely have to document your code, that readability is at the top of your priorities. Also people who don't have a cargo cult mentality too. For instance, the same person who asked me about design patterns in a job interview, later told me that something like a List of Map of Vector of Map of Set (in Java) is very readable. Why would someone ask me about design patterns if they can't even grasp encapsulation? These kind of things are the norm. I've seen many examples. I've seen worse than that too, from very well paid senior devs, by the way. Every second that you spend working with people with such lack of common sense and clear thinking, you are effectively losing money by being terribly inefficient with your time. Yet, with all these inefficiencies, the average developer earns a high salary. So I tried working on my own then, although I don't like the idea. I prefer healthy exchange of opinions and ideas and task division. I then did a bit of online freelancing for a while but I think working in a sweatshop might be more enjoyable. Also, I studied computer engineering and you are in an environment in which your client will presume you don't have any formal education because there is no way to prove it. Again, you are undervalued. You could try building a product, yes. But, of course, luck is a big factor. I wonder if there is a way to work in something you can do well, software development, and be valued for the quality of your work and be paid accordingly, and where you and only you get fairly paid for the value you generate. I know that what I have written seems somehow unlikely but I strongly feel this way. Hopefully someone will understand me and has already figured this out. I don't think I'm alone in this kind of feeling.

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  • Introduction to WebCenter Personalization: &ldquo;The Conductor&rdquo;

    - by Steve Pepper
    There are some new faces in the town of WebCenter with the latest 11g PS3 release.  A new component has introduced itself as "Oracle WebCenter Personalization", a.k.a WCP, to simplify delivery of a personalized experience and content to end users.  This posting reviews one of the primary components within WCP: "The Conductor". The Conductor: This ain't just an ordinary cloud... One of the founding principals behind WebCenter Personalization was to provide an open client-side API that remains independent of the technology invoking it, in addition to independence from the architecture running it.  The Conductor delivers this, and much, much more. The Conductor is the engine behind WebCenter Personalization that allows flow-based documents, called "Scenarios", to be managed and executed on the server-side through a well published and RESTful api.      The Conductor also supports an extensible model for custom provider integration that can be easily invoked within a Scenario to promote seamless integration with existing business assets. Introducing the Scenario Conductor Scenarios are declarative offline-authored documents using the custom Personalization JDeveloper bundle included with WebCenter.  A Scenario contains one (or more) statements that can: Create variables that are scoped to the current execution context Iterate over collections, or loop until a specific condition is met Execute one or more statements when a condition is met Invoke other scenarios that exist within the same namespace Invoke a data provider that integrates with custom applications Once a variable is assigned within the Scenario's execution context, it can be referenced anywhere within the same Scenario using the common Expression Language syntax used in J2EE web containers. Scenarios are then published and tested to the Integrated WebLogic Server domain, or published remotely to other domains running WebCenter Personalization. Various Client-side Models The Conductor server API is built upon RESTful services that support a wide variety of clients able to communicate over HTTP.  The Conductor supports the following client-side models: REST:  Popular browser-based languages can be used to manage and execute Conductor Scenarios.  There are other public methods to retrieve configured provider metadata that can be used by custom applications. The Conductor currently supports XML and JSON for it's API syntax. Java: WebCenter Personalization delivers a robust and light-weight java client with the popular Jersey framework as it's foundation.  It has never been easier to write a remote java client to manage remote RESTful services. Expression Language (EL): Allow the results of Scenario execution to control your user interface or embed personalized content using the session-scoped managed bean.  The EL client can also be used in straight JSP pages with minimal configuration. Extensible Provider Framework The Conductor supports a pluggable provider framework for integrating custom code with Scenario execution.  There are two types of providers supported by the Conductor: Function Provider: Function Providers are simple java annotated classes with static methods that are meant to be served as utilities.  Some common uses would include: object creation or instantiation, data transformation, and the like.  Function Providers can be invoked using the common EL syntax from variable assignments, conditions, and loops. For example:  ${myUtilityClass:doStuff(arg1,arg2))} If you are familiar with EL Functions, Function Providers are based on the same concept. Data Provider: Like Function Providers, Data Providers are annotated java classes, but they must adhere to a much more strict object model.  Data Providers have access to a wealth of Conductor services, such as: Access to namespace-scoped configuration API that can be managed by Oracle Enterprise Manager, Scenario execution context for expression resolution, and more.  Oracle ships with three out-of-the-box data providers that supports integration with: Standardized Content Servers(CMIS),  Federated Profile Properties through the Properties Service, and WebCenter Activity Graph. Useful References If you are looking to immediately get started writing your own application using WebCenter Personalization Services, you will find the following references helpful in getting you on your way: Personalizing WebCenter Applications Authoring Personalized Scenarios in JDeveloper Using Personalization APIs Externally Implementing and Calling Function Providers Implementing and Calling Data Providers

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  • Why Apple’s New SDK Limitation is So Offensive

    - by TStewartDev
    I am not an Apple fanboy, nor have I ever been. However, I have owned a Mac, an iPod, and an iPhone in my lifetime, and for more than a decade, I have defended Apple against the untruths that the haters so enjoy spewing. I encouraged my wife to buy a MacBook when she needed a new laptop two years ago, and I often recommend them to my friends and relatives. I have proudly and happily used my first generation iPhone for nearly three years. Now, for the first time in well over ten years, I find myself ready to swear off Apple and encourage everyone I know to do the same. I was disappointed when Apple wouldn't allow native apps, but I still bought the iPhone. I've stomached their ambiguous app approval process even though it's apparent that Steve may just reject your app because he doesn't like you or feels threatened by you (I'm still lamenting the rejection of the Google Voice app). But, as a developer, I can no longer tolerate Apple's terms and the kind of totalitarian control they indicate Apple wants. In case you are not already familiar, Apple has dictated in their OS 4.0 SDK license agreement (the now infamous Section 3.3.1) that all apps developed for the iPhone must be coded in C, C++, or Objective C, and moreover, that using any cross-compiling platforms is a violation of the agreement. For those of you who aren't developers, let me try to illustrate why this angers those of us who are. Imagine you're a professional writer. You've had articles published in some journals and magazines, and you've got a couple popular books out there, too. You've got an idea for a new book, and so you take it to your publisher. Your publisher agrees that it's a good idea. "But," says the publisher, "we want to hold our books to a tighter standard so that our readers get the experience we want them to have. Therefore, from now on, all our writers may only use words from this list of the 10,000 most common English words. Furthermore, if you cite any other works or quote anyone, they must comply with that same list, or you'll have to rewrite the entire work as well in case our readers want to look up your citation." What do you do? If your work is a children's book, this probably isn't a big deal to you. If it's an autobiography, textbook, or even a novel, though, you're going to have a lot of trouble describing your content with only common words. It's going to take you longer to complete your book, too, since you'll be looking up less common words frequently to see if you can use them. You could always go to another publisher, but this one has the best ability to distribute your book. The next largest distributor can only do a quarter as much. You could abandon the project altogether, but then everyone loses. Isn't this a silly scenario? Who would put such a limitation on writers? Yet this is very much what Apple is doing. They are using their dominant position in the market to coerce developers to write their apps exclusively for the iPhone OS by making it too expensive to write for multiple platforms. It is at least a threefold attack, striking at Adobe who is set to release a compiler that lets Flash source be compiled to iPhone binaries; striking at Google whose Android platform stands the best chance at the moment of providing serious competition to the iPhone; and reinforcing their own strong position by keeping popular apps exclusively to iPhone. And while developers are already very upset about this, the sad fact is that most of us will cave and give in to Apple because consumers don't know any better. They will continue to buy Apple's toy forcing developers to play Apple's maniacal game in order to make any money, at least until Steve Jobs decides he doesn't like them or he intends to release a competing application (bye-bye OpenFeint). Apple has been kept in check on the desktop front by a very dominant Microsoft, but I'm afraid that their success with iPods, iTunes, and iPhones has created a monster that we may have to bear until it is slain by an anti-trust suit or dies with the retirement of Steve Jobs.

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  • MVC Communication Pattern

    - by Kedu
    This is kind of a follow up question to this http://stackoverflow.com/questions/23743285/model-view-controller-and-callbacks, but I wanted to post it separately, because its kind of a different topic. I'm working on a multiplayer cardgame for the Android platform. I split the project into MVC which fits the needs pretty good, but I'm currently stuck because I can't figure out a good way to communicate between the different parts. I have everything setup and working with the controller being a big state machine, which is called over and over from the gameloop, and calls getter methods from the GUI and the android/network part to get the input. The input itself in the GUI and network is set by inputlisteners that set a local variable which I read in the getter method. So far so good, this is working. But my problem is, the controller has to check every input separately,so if I want to add an input I have to check in which states its valid and call the getter method from all these states. This is not good, and lets the code look pretty ugly, makes additions uncomfortable and adds redundance. So what I've got from the question I mentioned above is that some kind of command or event pattern will fit my needs. What I want to do is to create a shared and threadsafe queue in the controller and instead of calling all these getter methods, I just check the queue for new input and proceed it. On the other side, the GUI and network don't have all these getters, but instead create an event or command and send it to the controller through, for example, observer/observable. Now my problem: I can't figure out a way, for these commands/events to fit a common interface (which the queue can store) and still transport different kind of data (button clicks, cards that are played, the player id the command comes from, synchronization data etc.). If I design the communication as command pattern, I have to stick all the information that is needed to execute the command into it when its created, that's impossible because the GUI or network has no knowledge of all the things the controller needs to execute stuff that needs to be done when for example a card is played. I thought about getting this stuff into the command when executing it. But over all the different commands I have, I would need all the information the controller has, and thus give the command a reference to the controller which would make everything in it public, which is real bad design I guess. So, I could try some kind of event pattern. I have to transport data in the event. So, like the command, I would have an interface, which all events have in common, and can be stored in the shared queue. I could create a big enum with all the different events that a are possible, save one of these enums in the actual event, and build a big switch case for the events, to proceed different stuff for different events. The problem here: I have different data for all the events. But I need a common interface, to store the events in a queue. How do I get the specific data, if I can only access the event through the interface? Even if that wouldn't be a problem, I'm creating another big switch case, which looks ugly, and when i want to add a new event, I have to create the event itself, the case, the enum, and the method that's called with the data. I could of course check the event with the enum and cast it to its type, so I can call event type specific methods that give me the data I need, but that looks like bad design too.

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  • edited and reversed changes on .htaccess - site starts redirecting to .comindex.php/

    - by Aurigae
    Site is a Joomla 2.5 site. I wanted to add a non www to www redirect to the htaccess file, did so, then the redirection went mad, reversed but still the site redirects. When i click view site in admin panel, i get linked to http://domain.comindex.php/ The website is http://www.domain.com Visiting the website URL works without www, but once you click on projects it acts mad too. Projects is managed with joomshopping extension. EDIT: the redirect also happens when rewrite is deactivated in admin panel. ## # @package Joomla # @copyright Copyright (C) 2005 - 2012 Open Source Matters. All rights reserved. # @license GNU General Public License version 2 or later; see LICENSE.txt ## ## # READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE! # # The line just below this section: 'Options +FollowSymLinks' may cause problems # with some server configurations. It is required for use of mod_rewrite, but may already # be set by your server administrator in a way that dissallows changing it in # your .htaccess file. If using it causes your server to error out, comment it out (add # to # beginning of line), reload your site in your browser and test your sef url's. If they work, # it has been set by your server administrator and you do not need it set here. ## ## Can be commented out if causes errors, see notes above. Options +FollowSymLinks ## Mod_rewrite in use. RewriteEngine On ## Begin - Rewrite rules to block out some common exploits. # If you experience problems on your site block out the operations listed below # This attempts to block the most common type of exploit `attempts` to Joomla! # # Block out any script trying to base64_encode data within the URL. RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR] # Block out any script that includes a <script> tag in URL. RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR] # Block out any script trying to set a PHP GLOBALS variable via URL. RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR] # Block out any script trying to modify a _REQUEST variable via URL. RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2}) # Return 403 Forbidden header and show the content of the root homepage RewriteRule .* index.php [F] # ## End - Rewrite rules to block out some common exploits. ## Begin - Custom redirects # # If you need to redirect some pages, or set a canonical non-www to # www redirect (or vice versa), place that code here. Ensure those # redirects use the correct RewriteRule syntax and the [R=301,L] flags. # ## End - Custom redirects ## # Uncomment following line if your webserver's URL # is not directly related to physical file paths. # Update Your Joomla! Directory (just / for root). ## # RewriteBase / ## Begin - Joomla! core SEF Section. # RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}] # # If the requested path and file is not /index.php and the request # has not already been internally rewritten to the index.php script RewriteCond %{REQUEST_URI} !^/index\.php # and the request is for something within the component folder, # or for the site root, or for an extensionless URL, or the # requested URL ends with one of the listed extensions RewriteCond %{REQUEST_URI} /component/|(/[^.]*|\.(php|html?|feed|pdf|vcf|raw))$ [NC] # and the requested path and file doesn't directly match a physical file RewriteCond %{REQUEST_FILENAME} !-f # and the requested path and file doesn't directly match a physical folder RewriteCond %{REQUEST_FILENAME} !-d # internally rewrite the request to the index.php script RewriteRule .* index.php [L] # ## End - Joomla! core SEF Section. Redirect 301 /index.html /index.php Redirect 301 /services /project Redirect 301 /projects/projects.html /project Redirect 301 /projects/project1.html /project Redirect 301 /projects/project2.html /project Redirect 301 /projects /project Redirect 301 /keypersonnel.html /about-agrin/keystaff Redirect 301 /cooperation.htm /about-agrin/intcoop Redirect 301 /member.html /about-agrin/memberships Redirect 301 /contact.html /contacts Redirect 301 /hr.htm /jobs Redirect 301 /index.php/404 /index.php

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  • An Introduction to Meteor

    - by Stephen.Walther
    The goal of this blog post is to give you a brief introduction to Meteor which is a framework for building Single Page Apps. In this blog entry, I provide a walkthrough of building a simple Movie database app. What is special about Meteor? Meteor has two jaw-dropping features: Live HTML – If you make any changes to the HTML, CSS, JavaScript, or data on the server then every client shows the changes automatically without a browser refresh. For example, if you change the background color of a page to yellow then every open browser will show the new yellow background color without a refresh. Or, if you add a new movie to a collection of movies, then every open browser will display the new movie automatically. With Live HTML, users no longer need a refresh button. Changes to an application happen everywhere automatically without any effort. The Meteor framework handles all of the messy details of keeping all of the clients in sync with the server for you. Latency Compensation – When you modify data on the client, these modifications appear as if they happened on the server without any delay. For example, if you create a new movie then the movie appears instantly. However, that is all an illusion. In the background, Meteor updates the database with the new movie. If, for whatever reason, the movie cannot be added to the database then Meteor removes the movie from the client automatically. Latency compensation is extremely important for creating a responsive web application. You want the user to be able to make instant modifications in the browser and the framework to handle the details of updating the database without slowing down the user. Installing Meteor Meteor is licensed under the open-source MIT license and you can start building production apps with the framework right now. Be warned that Meteor is still in the “early preview” stage. It has not reached a 1.0 release. According to the Meteor FAQ, Meteor will reach version 1.0 in “More than a month, less than a year.” Don’t be scared away by that. You should be aware that, unlike most open source projects, Meteor has financial backing. The Meteor project received an $11.2 million round of financing from Andreessen Horowitz. So, it would be a good bet that this project will reach the 1.0 mark. And, if it doesn’t, the framework as it exists right now is still very powerful. Meteor runs on top of Node.js. You write Meteor apps by writing JavaScript which runs both on the client and on the server. You can build Meteor apps on Windows, Mac, or Linux (Although the support for Windows is still officially unofficial). If you want to install Meteor on Windows then download the MSI from the following URL: http://win.meteor.com/ If you want to install Meteor on Mac/Linux then run the following CURL command from your terminal: curl https://install.meteor.com | /bin/sh Meteor will install all of its dependencies automatically including Node.js. However, I recommend that you install Node.js before installing Meteor by installing Node.js from the following address: http://nodejs.org/ If you let Meteor install Node.js then Meteor won’t install NPM which is the standard package manager for Node.js. If you install Node.js and then you install Meteor then you get NPM automatically. Creating a New Meteor App To get a sense of how Meteor works, I am going to walk through the steps required to create a simple Movie database app. Our app will display a list of movies and contain a form for creating a new movie. The first thing that we need to do is create our new Meteor app. Open a command prompt/terminal window and execute the following command: Meteor create MovieApp After you execute this command, you should see something like the following: Follow the instructions: execute cd MovieApp to change to your MovieApp directory, and run the meteor command. Executing the meteor command starts Meteor on port 3000. Open up your favorite web browser and navigate to http://localhost:3000 and you should see the default Meteor Hello World page: Open up your favorite development environment to see what the Meteor app looks like. Open the MovieApp folder which we just created. Here’s what the MovieApp looks like in Visual Studio 2012: Notice that our MovieApp contains three files named MovieApp.css, MovieApp.html, and MovieApp.js. In other words, it contains a Cascading Style Sheet file, an HTML file, and a JavaScript file. Just for fun, let’s see how the Live HTML feature works. Open up multiple browsers and point each browser at http://localhost:3000. Now, open the MovieApp.html page and modify the text “Hello World!” to “Hello Cruel World!” and save the change. The text in all of the browsers should update automatically without a browser refresh. Pretty amazing, right? Controlling Where JavaScript Executes You write a Meteor app using JavaScript. Some of the JavaScript executes on the client (the browser) and some of the JavaScript executes on the server and some of the JavaScript executes in both places. For a super simple app, you can use the Meteor.isServer and Meteor.isClient properties to control where your JavaScript code executes. For example, the following JavaScript contains a section of code which executes on the server and a section of code which executes in the browser: if (Meteor.isClient) { console.log("Hello Browser!"); } if (Meteor.isServer) { console.log("Hello Server!"); } console.log("Hello Browser and Server!"); When you run the app, the message “Hello Browser!” is written to the browser JavaScript console. The message “Hello Server!” is written to the command/terminal window where you ran Meteor. Finally, the message “Hello Browser and Server!” is execute on both the browser and server and the message appears in both places. For simple apps, using Meteor.isClient and Meteor.isServer to control where JavaScript executes is fine. For more complex apps, you should create separate folders for your server and client code. Here are the folders which you can use in a Meteor app: · client – This folder contains any JavaScript which executes only on the client. · server – This folder contains any JavaScript which executes only on the server. · common – This folder contains any JavaScript code which executes on both the client and server. · lib – This folder contains any JavaScript files which you want to execute before any other JavaScript files. · public – This folder contains static application assets such as images. For the Movie App, we need the client, server, and common folders. Delete the existing MovieApp.js, MovieApp.html, and MovieApp.css files. We will create new files in the right locations later in this walkthrough. Combining HTML, CSS, and JavaScript Files Meteor combines all of your JavaScript files, and all of your Cascading Style Sheet files, and all of your HTML files automatically. If you want to create one humongous JavaScript file which contains all of the code for your app then that is your business. However, if you want to build a more maintainable application, then you should break your JavaScript files into many separate JavaScript files and let Meteor combine them for you. Meteor also combines all of your HTML files into a single file. HTML files are allowed to have the following top-level elements: <head> — All <head> files are combined into a single <head> and served with the initial page load. <body> — All <body> files are combined into a single <body> and served with the initial page load. <template> — All <template> files are compiled into JavaScript templates. Because you are creating a single page app, a Meteor app typically will contain a single HTML file for the <head> and <body> content. However, a Meteor app typically will contain several template files. In other words, all of the interesting stuff happens within the <template> files. Displaying a List of Movies Let me start building the Movie App by displaying a list of movies. In order to display a list of movies, we need to create the following four files: · client\movies.html – Contains the HTML for the <head> and <body> of the page for the Movie app. · client\moviesTemplate.html – Contains the HTML template for displaying the list of movies. · client\movies.js – Contains the JavaScript for supplying data to the moviesTemplate. · server\movies.js – Contains the JavaScript for seeding the database with movies. After you create these files, your folder structure should looks like this: Here’s what the client\movies.html file looks like: <head> <title>My Movie App</title> </head> <body> <h1>Movies</h1> {{> moviesTemplate }} </body>   Notice that it contains <head> and <body> top-level elements. The <body> element includes the moviesTemplate with the syntax {{> moviesTemplate }}. The moviesTemplate is defined in the client/moviesTemplate.html file: <template name="moviesTemplate"> <ul> {{#each movies}} <li> {{title}} </li> {{/each}} </ul> </template> By default, Meteor uses the Handlebars templating library. In the moviesTemplate above, Handlebars is used to loop through each of the movies using {{#each}}…{{/each}} and display the title for each movie using {{title}}. The client\movies.js JavaScript file is used to bind the moviesTemplate to the Movies collection on the client. Here’s what this JavaScript file looks like: // Declare client Movies collection Movies = new Meteor.Collection("movies"); // Bind moviesTemplate to Movies collection Template.moviesTemplate.movies = function () { return Movies.find(); }; The Movies collection is a client-side proxy for the server-side Movies database collection. Whenever you want to interact with the collection of Movies stored in the database, you use the Movies collection instead of communicating back to the server. The moviesTemplate is bound to the Movies collection by assigning a function to the Template.moviesTemplate.movies property. The function simply returns all of the movies from the Movies collection. The final file which we need is the server-side server\movies.js file: // Declare server Movies collection Movies = new Meteor.Collection("movies"); // Seed the movie database with a few movies Meteor.startup(function () { if (Movies.find().count() == 0) { Movies.insert({ title: "Star Wars", director: "Lucas" }); Movies.insert({ title: "Memento", director: "Nolan" }); Movies.insert({ title: "King Kong", director: "Jackson" }); } }); The server\movies.js file does two things. First, it declares the server-side Meteor Movies collection. When you declare a server-side Meteor collection, a collection is created in the MongoDB database associated with your Meteor app automatically (Meteor uses MongoDB as its database automatically). Second, the server\movies.js file seeds the Movies collection (MongoDB collection) with three movies. Seeding the database gives us some movies to look at when we open the Movies app in a browser. Creating New Movies Let me modify the Movies Database App so that we can add new movies to the database of movies. First, I need to create a new template file – named client\movieForm.html – which contains an HTML form for creating a new movie: <template name="movieForm"> <fieldset> <legend>Add New Movie</legend> <form> <div> <label> Title: <input id="title" /> </label> </div> <div> <label> Director: <input id="director" /> </label> </div> <div> <input type="submit" value="Add Movie" /> </div> </form> </fieldset> </template> In order for the new form to show up, I need to modify the client\movies.html file to include the movieForm.html template. Notice that I added {{> movieForm }} to the client\movies.html file: <head> <title>My Movie App</title> </head> <body> <h1>Movies</h1> {{> moviesTemplate }} {{> movieForm }} </body> After I make these modifications, our Movie app will display the form: The next step is to handle the submit event for the movie form. Below, I’ve modified the client\movies.js file so that it contains a handler for the submit event raised when you submit the form contained in the movieForm.html template: // Declare client Movies collection Movies = new Meteor.Collection("movies"); // Bind moviesTemplate to Movies collection Template.moviesTemplate.movies = function () { return Movies.find(); }; // Handle movieForm events Template.movieForm.events = { 'submit': function (e, tmpl) { // Don't postback e.preventDefault(); // create the new movie var newMovie = { title: tmpl.find("#title").value, director: tmpl.find("#director").value }; // add the movie to the db Movies.insert(newMovie); } }; The Template.movieForm.events property contains an event map which maps event names to handlers. In this case, I am mapping the form submit event to an anonymous function which handles the event. In the event handler, I am first preventing a postback by calling e.preventDefault(). This is a single page app, no postbacks are allowed! Next, I am grabbing the new movie from the HTML form. I’m taking advantage of the template find() method to retrieve the form field values. Finally, I am calling Movies.insert() to insert the new movie into the Movies collection. Here, I am explicitly inserting the new movie into the client-side Movies collection. Meteor inserts the new movie into the server-side Movies collection behind the scenes. When Meteor inserts the movie into the server-side collection, the new movie is added to the MongoDB database associated with the Movies app automatically. If server-side insertion fails for whatever reasons – for example, your internet connection is lost – then Meteor will remove the movie from the client-side Movies collection automatically. In other words, Meteor takes care of keeping the client Movies collection and the server Movies collection in sync. If you open multiple browsers, and add movies, then you should notice that all of the movies appear on all of the open browser automatically. You don’t need to refresh individual browsers to update the client-side Movies collection. Meteor keeps everything synchronized between the browsers and server for you. Removing the Insecure Module To make it easier to develop and debug a new Meteor app, by default, you can modify the database directly from the client. For example, you can delete all of the data in the database by opening up your browser console window and executing multiple Movies.remove() commands. Obviously, enabling anyone to modify your database from the browser is not a good idea in a production application. Before you make a Meteor app public, you should first run the meteor remove insecure command from a command/terminal window: Running meteor remove insecure removes the insecure package from the Movie app. Unfortunately, it also breaks our Movie app. We’ll get an “Access denied” error in our browser console whenever we try to insert a new movie. No worries. I’ll fix this issue in the next section. Creating Meteor Methods By taking advantage of Meteor Methods, you can create methods which can be invoked on both the client and the server. By taking advantage of Meteor Methods you can: 1. Perform form validation on both the client and the server. For example, even if an evil hacker bypasses your client code, you can still prevent the hacker from submitting an invalid value for a form field by enforcing validation on the server. 2. Simulate database operations on the client but actually perform the operations on the server. Let me show you how we can modify our Movie app so it uses Meteor Methods to insert a new movie. First, we need to create a new file named common\methods.js which contains the definition of our Meteor Methods: Meteor.methods({ addMovie: function (newMovie) { // Perform form validation if (newMovie.title == "") { throw new Meteor.Error(413, "Missing title!"); } if (newMovie.director == "") { throw new Meteor.Error(413, "Missing director!"); } // Insert movie (simulate on client, do it on server) return Movies.insert(newMovie); } }); The addMovie() method is called from both the client and the server. This method does two things. First, it performs some basic validation. If you don’t enter a title or you don’t enter a director then an error is thrown. Second, the addMovie() method inserts the new movie into the Movies collection. When called on the client, inserting the new movie into the Movies collection just updates the collection. When called on the server, inserting the new movie into the Movies collection causes the database (MongoDB) to be updated with the new movie. You must add the common\methods.js file to the common folder so it will get executed on both the client and the server. Our folder structure now looks like this: We actually call the addMovie() method within our client code in the client\movies.js file. Here’s what the updated file looks like: // Declare client Movies collection Movies = new Meteor.Collection("movies"); // Bind moviesTemplate to Movies collection Template.moviesTemplate.movies = function () { return Movies.find(); }; // Handle movieForm events Template.movieForm.events = { 'submit': function (e, tmpl) { // Don't postback e.preventDefault(); // create the new movie var newMovie = { title: tmpl.find("#title").value, director: tmpl.find("#director").value }; // add the movie to the db Meteor.call( "addMovie", newMovie, function (err, result) { if (err) { alert("Could not add movie " + err.reason); } } ); } }; The addMovie() method is called – on both the client and the server – by calling the Meteor.call() method. This method accepts the following parameters: · The string name of the method to call. · The data to pass to the method (You can actually pass multiple params for the data if you like). · A callback function to invoke after the method completes. In the JavaScript code above, the addMovie() method is called with the new movie retrieved from the HTML form. The callback checks for an error. If there is an error then the error reason is displayed in an alert (please don’t use alerts for validation errors in a production app because they are ugly!). Summary The goal of this blog post was to provide you with a brief walk through of a simple Meteor app. I showed you how you can create a simple Movie Database app which enables you to display a list of movies and create new movies. I also explained why it is important to remove the Meteor insecure package from a production app. I showed you how to use Meteor Methods to insert data into the database instead of doing it directly from the client. I’m very impressed with the Meteor framework. The support for Live HTML and Latency Compensation are required features for many real world Single Page Apps but implementing these features by hand is not easy. Meteor makes it easy.

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  • Install Control Center Agent on Oracle Application Server

    - by qianqian.wu
    Control Center Agent (CCA) The Control Center Agent is the OWB component that runs the Template Mappings in the Oracle Containers for J2EE (OC4J) server; also referred to as the J2EE Runtime. The Control Center Agent provides a Java-based runtime environment that can be installed on Oracle and non-Oracle database hosts. The Control Center Agent provides fundamental infrastructure for the heterogeneous, Code Template-based mapping support and Web services-related features of OWB in this release. In Oracle Warehouse Builder 11gR2 the Control Center Agent, by default will run in the built-in OC4J that is bundled in the Oracle Home. Besides that, you also have ability to install the Control Center Agent in an Oracle Application Server install. In this article, you will find step-by-step instructions how to install the Control Center Agent on an Oracle Application Server instance. The instructions cover the following tasks: Task 1: Install and Configure the Application Server Task 2: Deploy the Control Center Agent to the Application Server Task 3: Optional Configuration Tasks   Task 1: Install and Configure the Application Server Before configuring the Application Server, you need to install it from Oracle Application Server CD-ROM, or by downloading the installation program from Oracle Technology Network (OTN). Once the installation is completed, you are ready to configure the Application Server. The purpose of the configuration task is to make sure the Control Center Agent ear file can be deployed and runs in the Application Server successfully. The essential configuration tasks are outlined below: · Modify the OC4J Startup Script · Set up Control Center Agent Server Side Logging · Set up Audit Table Data Source · Copy ct_permissions.properties File · Set up Security Roles for Control Center Agent · Create JMS Queues · Install JDBC Drivers to OC4J Modify the OC4J Startup Script The OC4J startup script “opmn.xml” is located in Application Server configuration directory, $AS_HOME/opmn/conf. $AS_HOME stands for the root home directory of the application server. Open the file opmn.xml in a text editor, and alter the contents of the file as displayed in the following sample. You need to make sure that: The MaxPerSize is set to 128M. This is to ensure that you allocate enough PermGen space to OC4J to run Control Center Agent. This will prevent java.lang.OutOfMemoryError when running the agent. The Python.path sets the path for the Python library files used by the Control Center Agent: jython_lib.zip and jython_owblib.jar. These two files are in the $OWB_HOME/owb/lib/int directory, where $OWB_HOME is the directory where owb is installed. · The km_security_needed determines whether restrictions will be applied to the kinds of operating system commands allowed to be executed by the OWB Code Template script executed by Control Center Agent. Setting km_security_needed to “true” enforces such restriction while setting it to “false” removes such restrictions. Set up Control Center Agent Server Side Logging Ensure that you are in the Application Server configuration directory, $AS_HOME/j2ee/home/config. Open the file j2ee-logging.xml in a text editor and add the following lines to the log handler section. The jrt-internal-log-handler is the handler used by Control Center Agent runtime logger to create log files. Then add the following entry into the loggers section to create the logger for Control Center Agent runtime auditing. Set up Audit Table Data Source To enable Audit Table logging, a managed data source and connection pool need to be set up before Control Center Agent deployment. Ensure that you are in the Application Server configuration directory, $AS_HOME/j2ee/home/config. Open the file data-sources.xml in a text editor. Define the audit data source shown below in the file, <managed-data-source name="AuditDS" connection-pool-name="OWBSYS Audit   Connection Pool" jndi-name="jdbc/AuditDS"/> <connection-pool name="OWBSYS Audit Connection Pool">   <connection-factory factory-class="oracle.jdbc.pool.OracleDataSource"     user="owbsys_audit" password="owbsys_audit"     url="jdbc:oracle:thin:@//localhost:1521/ORCL"/> </connection-pool> Copy ct_permissions.properties File The ct_permissions.properties can be obtained from $OWB_HOME /owb/jrt/config/ directory. You need to copy the file to $AS_HOME/j2ee/home/config directory.This properties file takes effect when the setting km-security is set to true in Control Center Agent. By default the ALLOWED_CMD is commented out in ct_permissions.properties file. This prevents all system command from being invoked from scripts executed in Control Center Agent (when km-security is set to true). To allow certain system commands to be invoked, ALLOWED_CMD needs to be uncommented out, and the system commands (allowed to be invoked) need to be added to the ALLOWED_CMD. Set up Security Roles for Control Center Agent You can set up the Control Center Agent security roles through Oracle Enterprise Manager. In a web browser, navigate to Enterprise Manager Homepage (e.g. http://hostname:8889/em). 1. Log in using the oc4jadmin credentials. After the Cluster Topology page is loaded, click home (the OC4J instance). This takes you to the home page of the OC4J instance. On the OC4J home screen, click the Administration tab. On the Administration Tasks screen, expand Security. Click the task icon next to Security Providers. 2. On Security Providers page click on the button “Instance Level Security”. On Instance Level Security page, go to “Realms” tab. You will see a row for the default realm “jazn.com” in the results table. It has a “Roles” column and a “Users” column. Click on the number in “Roles” column. In the “Roles” page it will display all the roles available for the realm. Click on “Create” button to create a new role “OWB_J2EE_ EXECUTOR”. 3. On the Add Role screen, enter Name OWB_J2EE_EXECUTOR, and click OK. 4. Follow the same steps as before, and create a new role “OWB_J2EE_OPERATOR”. 5. Assign role “oc4j-administrators” and “OWB_J2EE_EXECUTOR” to the role “OWB_J2EE_OPERATOR” by moving these roles from “Available Roles” and click “OK” to save. 6. Go back to Instance Level Security page and create a new role “OWB_J2EE_ADMINISTRATOR”. 7. Assign roles “OWB_J2EE_ OPERATOR” and “OWB_J2EE_EXECUTOR” to the role “OWB_J2EE_ ADMINISTRATOR” by moving these roles from “Available Roles” and click “OK” to save. 8.Go back to Instance Level Security page. This time, click on the number in “Users” column for the realm “jazn.com”. In the “Users” page, it shows all the users defined for this realm. Locate the user “oc4jadmin” in the results table and click on it. 9. Assign the roles “OWB_J2EE_ADMINISTRATOR” and “oc4j-app-administrators” to this user by moving the role from the “Available Roles” selection box to “Selected Roles” box and click “Apply” to save. 10. Go back to Instance Level Security page and create a new role “OWB_INTERNAL_USERS”, assign no user or role to this role. Simply click “OK” to create this role. Now you have finished creating the security roles required for Control Center Agent. Create JMS Queues You need to create two JMS queues for Control Center Agent: owbQueue and abort_owbQueue. 1. Now go to OC4J home Page. On the OC4J home screen, click the Administration tab. On the Administration Tasks screen, expand Services and then expand Enterprise Messaging Service. Click the task icon next to JMS Destinations. 2. On JMS Destinations page, click “Create New” button to create a new JMS queue. On Add Destination page, choose “Queue” as Destination Type. Put “owbQueue” as Destination Name. Select “In Memory Persistence Only” as the Persistence Type and put “jms/owbQueue” as JNDI Location and click on “OK” to finish. 3. Follow the same instruction as above to create the owb_abortQueue. Now you have finished creating the JMS queues required for Control Center Agent. Install JDBC Drivers to OC4J In order to execute Code Templates using commercial databases other than Oracle, e.g. DB2, SQL Server etc, the corresponding jdbc driver files need to be added to $AS_HOME/j2ee/home/applib directory. 1. To install other JDBC drivers to OC4J, first obtain the .jar file containing the JDBC driver. All the external JDBC drivers .jar files can be found in the directory: $OWB_HOME/owb/lib/ext/. For DB2, the files needed are db2jcc.jar and db2jcc_license_cu.jar. For SQL Server the file is sqljdbc.jar. For sunopsis JDBC drivers, the file needed is snpsxmlo.jar. 2. Copy the required JDBC driver file into the directory $AS_HOME/j2ee/home/applib. Now you have finished the Application Server configuration. To make the configuration to take an effect, you need to restart the Application Server.   Task 2: Deploy the Control Center Agent to the Application Server Now you can deploy the Control Center Agent to the Application Server. In a web browser, navigate to Enterprise Manager Homepage (e.g. http://hostname:8889/em). 1. Log in using the oc4jadmin credentials. After the Cluster Topology page is loaded, click home (the OC4J instance). This takes you to the home page of the OC4J instance. On the OC4J home screen, click the Applications tab. Click Deploy to begin deploying Control Center Agent. 2. On the Deploy: Select Archive screen, under Archive, select Archive is present on local host. Upload the archive to the server where Application Server Control is running. Click Browse and locate the jrt.ear file in the $OWB_HOME/owb/jrt/applications directory. Under Deployment Plan, select Automatically create a new deployment plan. Click Next. 3. Wait for the ear file to be uploaded to Application Server. On the Deploy: Application Attributes screen, enter Application Name jrt, and Context Root jrt. Leave the other attributes at their default values. Click Next. 4. On Deploy: Deployment Settings screen, leave all attributes at their default values, and click Deploy. This will take about 1 minute or so and when the application is deployed successfully, a confirmation message will be displayed. Now the Control Center Agent is started automatically. Go back to OC4J home page and click on Applications tab to make sure the deployed application jrt is showing in the applications list.   Task 3: Optional Configuration Tasks The optional configuration tasks contain: · Secure Control Center Agent Web Service · Setting the PATH Environment Variable Secure Control Center Agent Web Service If you want to use JRTWebService with a secure website, you need to do the following steps, 1. Create a file “secure-web-site.xml” in the $AS_HOME/j2ee/home/config directory. The file can be obtained from $OWB_HOME/owb/jrt/config directory. A sample secure-web-site.xml is shown as below. We need to modify the “protocol” to “https”, and “secure” to “true”, also choose an port as the secure http port. Also we need to add the entry “ssl-config” in the file. Remember to use the absolute path for the key store file. 2. Modify the file “server.xml” that is located at $AS_HOME/j2ee/home/config directory. Then add the <web-site> element in the file for the secure-web-site. 3. Create a key store file “serverkeystore.jks” in the $AS_HOME/j2ee/home/config directory. The file can be obtained from $OWB_HOME/owb/jrt/config directory. After the three files are altered, restart the application server. Now you can access the JRTWebService in SSL way through https://hostname:4443/jrt/webservice. Setting the PATH Environment Variable Sometimes, some system commands such as linux ls, sh etc, can not be executed successfully during the script execution due to they are not found in PATH. To ensure they work normally, you can setup the environment variable PATH. Let’s navigate to the Enterprise Manager Homepage. 1. Go to OC4J home screen and click the Administration tab. Expand Administration Tasks, then expand Properties. Click the task icon next to Server Properties. 2. On the Server Properties screen, scroll down to Environment Variables section. Under Environment Variables, click Add Another Row. Enter PATH in Name, and fill Value with directories that contain the system commands. Click Apply.   After you work through this article, I believe you have developed a deeper understanding of the Control Center Agent installation process, and you can apply this knowledge in other installation plan such as Control Center Agent installation on Standalone OC4J.

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  • The case of the phantom ADF developer (and other yarns)

    - by Chris Muir
    A few years of ADF experience means I see common mistakes made by different developers, some I regularly make myself.  This post is designed to assist beginners to Oracle JDeveloper Application Development Framework (ADF) avoid a common ADF pitfall, the case of the phantom ADF developer [add Scooby-Doo music here]. ADF Business Components - triggers, default table values and instead of views. Oracle's JDeveloper tutorials help with the A-B-Cs of ADF development, typically built on the nice 'n safe demo schema provided by with the Oracle database such as the HR demo schema. However it's not too long until ADF beginners, having built up some confidence from learning with the tutorials and vanilla demo schemas, start building ADF Business Components based upon their own existing database schema objects.  This is where unexpected problems can sneak in. The crime Developers may encounter a surprising error at runtime when editing a record they just created or updated and committed to the database, based on their own existing tables, namely the error: JBO-25014: Another user has changed the row with primary key oracle.jbo.Key[x] ...where X is the primary key value of the row at hand.  In a production environment with multiple users this error may be legit, one of the other users has updated the row since you queried it.  Yet in a development environment this error is just plain confusing.  If developers are isolated in their own database, creating and editing records they know other users can't possibly be working with, or all the other developers have gone home for the day, how is this error possible? There are no other users?  It must be the phantom ADF developer! [insert dramatic music here] The following picture is what you'll see in the Business Component Browser, and you'll receive a similar error message via an ADF Faces page: A false conclusion What can possibly cause this issue if it isn't our phantom ADF developer?  Doesn't ADF BC implement record locking, locking database records when the row is modified in the ADF middle-tier by a user?  How can our phantom ADF developer even take out a lock if this is the case?  Maybe ADF has a bug, maybe ADF isn't implementing record locking at all?  Shouldn't we see the error "JBO-26030: Failed to lock the record, another user holds the lock" as we attempt to modify the record, why do we see JBO-25014? : Let's verify that ADF is in fact issuing the correct SQL LOCK-FOR-UPDATE statement to the database. First we need to verify ADF's locking strategy.  It is determined by the Application Module's jbo.locking.mode property.  The default (as of JDev 11.1.1.4.0 if memory serves me correct) and recommended value is optimistic, and the other valid value is pessimistic. Next we need a mechanism to check that ADF is issuing the LOCK statements to the database.  We could ask DBAs to monitor locks with OEM, but optimally we'd rather not involve overworked DBAs in this process, so instead we can use the ADF runtime setting –Djbo.debugoutput=console.  At runtime this options turns on instrumentation within the ADF BC layer, which among a lot of extra detail displayed in the log window, will show the actual SQL statement issued to the database, including the LOCK statement we're looking to confirm. Setting our locking mode to pessimistic, opening the Business Components Browser of a JSF page allowing us to edit a record, say the CHARGEABLE field within a BOOKINGS record where BOOKING_NO = 1206, upon editing the record see among others the following log entries: [421] Built select: 'SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings'[422] Executing LOCK...SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings WHERE BOOKING_NO=:1 FOR UPDATE NOWAIT[423] Where binding param 1: 1206  As can be seen on line 422, in fact a LOCK-FOR-UPDATE is indeed issued to the database.  Later when we commit the record we see: [441] OracleSQLBuilder: SAVEPOINT 'BO_SP'[442] OracleSQLBuilder Executing, Lock 1 DML on: BOOKINGS (Update)[443] UPDATE buf Bookings>#u SQLStmtBufLen: 210, actual=62[444] UPDATE BOOKINGS Bookings SET CHARGEABLE=:1 WHERE BOOKING_NO=:2[445] Update binding param 1: N[446] Where binding param 2: 1206[447] BookingsView1 notify COMMIT ... [448] _LOCAL_VIEW_USAGE_model_Bookings_ResourceTypesView1 notify COMMIT ... [449] EntityCache close prepared statement ....and as a result the changes are saved to the database, and the lock is released. Let's see what happens when we use the optimistic locking mode, this time to change the same BOOKINGS record CHARGEABLE column again.  As soon as we edit the record we see little activity in the logs, nothing to indicate any SQL statement, let alone a LOCK has been taken out on the row. However when we save our records by issuing a commit, the following is recorded in the logs: [509] OracleSQLBuilder: SAVEPOINT 'BO_SP'[510] OracleSQLBuilder Executing doEntitySelect on: BOOKINGS (true)[511] Built select: 'SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings'[512] Executing LOCK...SELECT BOOKING_NO, EVENT_NO, RESOURCE_CODE, CHARGEABLE, MADE_BY, QUANTITY, COST, STATUS, COMMENTS FROM BOOKINGS Bookings WHERE BOOKING_NO=:1 FOR UPDATE NOWAIT[513] Where binding param 1: 1205[514] OracleSQLBuilder Executing, Lock 2 DML on: BOOKINGS (Update)[515] UPDATE buf Bookings>#u SQLStmtBufLen: 210, actual=62[516] UPDATE BOOKINGS Bookings SET CHARGEABLE=:1 WHERE BOOKING_NO=:2[517] Update binding param 1: Y[518] Where binding param 2: 1205[519] BookingsView1 notify COMMIT ... [520] _LOCAL_VIEW_USAGE_model_Bookings_ResourceTypesView1 notify COMMIT ... [521] EntityCache close prepared statement Again even though we're seeing the midtier delay the LOCK statement until commit time, it is in fact occurring on line 412, and released as part of the commit issued on line 419.  Therefore with either optimistic or pessimistic locking a lock is indeed issued. Our conclusion at this point must be, unless there's the unlikely cause the LOCK statement is never really hitting the database, or the even less likely cause the database has a bug, then ADF does in fact take out a lock on the record before allowing the current user to update it.  So there's no way our phantom ADF developer could even modify the record if he tried without at least someone receiving a lock error. Hmm, we can only conclude the locking mode is a red herring and not the true cause of our problem.  Who is the phantom? At this point we'll need to conclude that the error message "JBO-25014: Another user has changed" is somehow legit, even though we don't understand yet what's causing it. This leads onto two further questions, how does ADF know another user has changed the row, and what's been changed anyway? To answer the first question, how does ADF know another user has changed the row, the Fusion Guide's section 4.10.11 How to Protect Against Losing Simultaneous Updated Data , that details the Entity Object Change-Indicator property, gives us the answer: At runtime the framework provides automatic "lost update" detection for entity objects to ensure that a user cannot unknowingly modify data that another user has updated and committed in the meantime. Typically, this check is performed by comparing the original values of each persistent entity attribute against the corresponding current column values in the database at the time the underlying row is locked. Before updating a row, the entity object verifies that the row to be updated is still consistent with the current state of the database.  The guide further suggests to make this solution more efficient: You can make the lost update detection more efficient by identifying any attributes of your entity whose values you know will be updated whenever the entity is modified. Typical candidates include a version number column or an updated date column in the row.....To detect whether the row has been modified since the user queried it in the most efficient way, select the Change Indicator option to compare only the change-indicator attribute values. We now know that ADF BC doesn't use the locking mechanism at all to protect the current user against updates, but rather it keeps a copy of the original record fetched, separate to the user changed version of the record, and it compares the original record against the one in the database when the lock is taken out.  If values don't match, be it the default compare-all-columns behaviour, or the more efficient Change Indicator mechanism, ADF BC will throw the JBO-25014 error. This leaves one last question.  Now we know the mechanism under which ADF identifies a changed row, what we don't know is what's changed and who changed it? The real culprit What's changed?  We know the record in the mid-tier has been changed by the user, however ADF doesn't use the changed record in the mid-tier to compare to the database record, but rather a copy of the original record before it was changed.  This leaves us to conclude the database record has changed, but how and by who? There are three potential causes: Database triggers The database trigger among other uses, can be configured to fire PLSQL code on a database table insert, update or delete.  In particular in an insert or update the trigger can override the value assigned to a particular column.  The trigger execution is actioned by the database on behalf of the user initiating the insert or update action. Why this causes the issue specific to our ADF use, is when we insert or update a record in the database via ADF, ADF keeps a copy of the record written to the database.  However the cached record is instantly out of date as the database triggers have modified the record that was actually written to the database.  Thus when we update the record we just inserted or updated for a second time to the database, ADF compares its original copy of the record to that in the database, and it detects the record has been changed – giving us JBO-25014. This is probably the most common cause of this problem. Default values A second reason this issue can occur is another database feature, default column values.  When creating a database table the schema designer can define default values for specific columns.  For example a CREATED_BY column could be set to SYSDATE, or a flag column to Y or N.  Default values are only used by the database when a user inserts a new record and the specific column is assigned NULL.  The database in this case will overwrite the column with the default value. As per the database trigger section, it then becomes apparent why ADF chokes on this feature, though it can only specifically occur in an insert-commit-update-commit scenario, not the update-commit-update-commit scenario. Instead of trigger views I must admit I haven't double checked this scenario but it seems plausible, that of the Oracle database's instead of trigger view (sometimes referred to as instead of views).  A view in the database is based on a query, and dependent on the queries complexity, may support insert, update and delete functionality to a limited degree.  In order to support fully insertable, updateable and deletable views, Oracle introduced the instead of view, that gives the view designer the ability to not only define the view query, but a set of programmatic PLSQL triggers where the developer can define their own logic for inserts, updates and deletes. While this provides the database programmer a very powerful feature, it can cause issues for our ADF application.  On inserting or updating a record in the instead of view, the record and it's data that goes in is not necessarily the data that comes out when ADF compares the records, as the view developer has the option to practically do anything with the incoming data, including throwing it away or pushing it to tables which aren't used by the view underlying query for fetching the data. Readers are at this point reminded that this article is specifically about how the JBO-25014 error occurs in the context of 1 developer on an isolated database.  The article is not considering how the error occurs in a production environment where there are multiple users who can cause this error in a legitimate fashion.  Assuming none of the above features are the cause of the problem, and optimistic locking is turned on (this error is not possible if pessimistic locking is the default mode *and* none of the previous causes are possible), JBO-25014 is quite feasible in a production ADF application if 2 users modify the same record. At this point under project timelines pressure, the obvious fix for developers is to drop both database triggers and default values from the underlying tables.  However we must be careful that these legacy constructs aren't used and assumed to be in place by other legacy systems.  Dropping the database triggers or default value that the existing Oracle Forms  applications assumes and requires to be in place could cause unexpected behaviour and bugs in the Forms application.  Proficient software engineers would recognize such a change may require a partial or full regression test of the existing legacy system, a potentially costly and timely exercise, not ideal. Solving the mystery once and for all Luckily ADF has built in functionality to deal with this issue, though it's not a surprise, as Oracle as the author of ADF also built the database, and are fully aware of the Oracle database's feature set.  At the Entity Object attribute level, the Refresh After Insert and Refresh After Update properties.  Simply selecting these instructs ADF BC after inserting or updating a record to the database, to expect the database to modify the said attributes, and read a copy of the changed attributes back into its cached mid-tier record.  Thus next time the developer modifies the current record, the comparison between the mid-tier record and the database record match, and JBO-25014: Another user has changed" is no longer an issue. [Post edit - as per the comment from Oracle's Steven Davelaar below, as he correctly points out the above solution will not work for instead-of-triggers views as it relies on SQL RETURNING clause which is incompatible with this type of view] Alternatively you can set the Change Indicator on one of the attributes.  This will work as long as the relating column for the attribute in the database itself isn't inadvertently updated.  In turn you're possibly just masking the issue rather than solving it, because if another developer turns the Change Indicator back on the original issue will return.

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  • How to shoot yourself in the foot (DO NOT Read in the office)

    - by TATWORTH
    Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2013/06/21/how-to-shoot-yourself-in-the-foot-do-not-read.aspxLet me make it absolutely clear - the following is:merely collated by your Geek from http://www.codeproject.com/Lounge.aspx?msg=3917012#xx3917012xxvery, very very funny so you read it in the presence of others at your own riskso here is the list - you have been warned!C You shoot yourself in the foot.   C++ You accidently create a dozen instances of yourself and shoot them all in the foot. Providing emergency medical assistance is impossible since you can't tell which are bitwise copies and which are just pointing at others and saying "That's me, over there."   FORTRAN You shoot yourself in each toe, iteratively, until you run out of toes, then you read in the next foot and repeat. If you run out of bullets, you continue anyway because you have no exception-handling facility.   Modula-2 After realizing that you can't actually accomplish anything in this language, you shoot yourself in the head.   COBOL USEing a COLT 45 HANDGUN, AIM gun at LEG.FOOT, THEN place ARM.HAND.FINGER on HANDGUN.TRIGGER and SQUEEZE. THEN return HANDGUN to HOLSTER. CHECK whether shoelace needs to be retied.   Lisp You shoot yourself in the appendage which holds the gun with which you shoot yourself in the appendage which holds the gun with which you shoot yourself in the appendage which holds...   BASIC Shoot yourself in the foot with a water pistol. On big systems, continue until entire lower body is waterlogged.   Forth Foot yourself in the shoot.   APL You shoot yourself in the foot; then spend all day figuring out how to do it in fewer characters.   Pascal The compiler won't let you shoot yourself in the foot.   Snobol If you succeed, shoot yourself in the left foot. If you fail, shoot yourself in the right foot.   HyperTalk Put the first bullet of the gun into foot left of leg of you. Answer the result.   Prolog You tell your program you want to be shot in the foot. The program figures out how to do it, but the syntax doesn't allow it to explain.   370 JCL You send your foot down to MIS with a 4000-page document explaining how you want it to be shot. Three years later, your foot comes back deep-fried.   FORTRAN-77 You shoot yourself in each toe, iteratively, until you run out of toes, then you read in the next foot and repeat. If you run out of bullets, you continue anyway because you still can't do exception-processing.   Modula-2 (alternative) You perform a shooting on what might be currently a foot with what might be currently a bullet shot by what might currently be a gun.   BASIC (compiled) You shoot yourself in the foot with a BB using a SCUD missile launcher.   Visual Basic You'll really only appear to have shot yourself in the foot, but you'll have so much fun doing it that you won't care.   Forth (alternative) BULLET DUP3 * GUN LOAD FOOT AIM TRIGGER PULL BANG! EMIT DEAD IF DROP ROT THEN (This takes about five bytes of memory, executes in two to ten clock cycles on any processor and can be used to replace any existing function of the language as well as in any future words). (Welcome to bottom up programming - where you, too, can perform compiler pre-processing instead of writing code)   APL (alternative) You hear a gunshot and there's a hole in your foot, but you don't remember enough linear algebra to understand what happened. or @#&^$%&%^ foot   Pascal (alternative) Same as Modula-2 except that the bullet is not the right type for the gun and your hand is blown off.   Snobol (alternative) You grab your foot with your hand, then rewrite your hand to be a bullet. The act of shooting the original foot then changes your hand/bullet into yet another foot (a left foot).   Prolog (alternative) You attempt to shoot yourself in the foot, but the bullet, failing to find its mark, backtracks to the gun, which then explodes in your face.   COMAL You attempt to shoot yourself in the foot with a water pistol, but the bore is clogged, and the pressure build-up blows apart both the pistol and your hand. or draw_pistol aim_at_foot(left) pull_trigger hop(swearing)   Scheme As Lisp, but none of the other appendages are aware of this happening.   Algol You shoot yourself in the foot with a musket. The musket is aesthetically fascinating and the wound baffles the adolescent medic in the emergency room.   Ada If you are dumb enough to actually use this language, the United States Department of Defense will kidnap you, stand you up in front of a firing squad and tell the soldiers, "Shoot at the feet." or The Department of Defense shoots you in the foot after offering you a blindfold and a last cigarette. or After correctly packaging your foot, you attempt to concurrently load the gun, pull the trigger, scream and shoot yourself in the foot. When you try, however, you discover that your foot is of the wrong type. or After correctly packing your foot, you attempt to concurrently load the gun, pull the trigger, scream, and confidently aim at your foot knowing it is safe. However the cordite in the round does an Unchecked Conversion, fires and shoots you in the foot anyway.   Eiffel   You create a GUN object, two FOOT objects and a BULLET object. The GUN passes both the FOOT objects a reference to the BULLET. The FOOT objects increment their hole counts and forget about the BULLET. A little demon then drives a garbage truck over your feet and grabs the bullet (both of it) on the way. Smalltalk You spend so much time playing with the graphics and windowing system that your boss shoots you in the foot, takes away your workstation and makes you develop in COBOL on a character terminal. or You send the message shoot to gun, with selectors bullet and myFoot. A window pops up saying Gunpowder doesNotUnderstand: spark. After several fruitless hours spent browsing the methods for Trigger, FiringPin and IdealGas, you take the easy way out and create ShotFoot, a subclass of Foot with an additional instance variable bulletHole. Object Oriented Pascal You perform a shooting on what might currently be a foot with what might currently be a bullet fired from what might currently be a gun.   PL/I You consume all available system resources, including all the offline bullets. The Data Processing & Payroll Department doubles its size, triples its budget, acquires four new mainframes and drops the original one on your foot. Postscript foot bullets 6 locate loadgun aim gun shoot showpage or It takes the bullet ten minutes to travel from the gun to your foot, by which time you're long since gone out to lunch. The text comes out great, though.   PERL You stab yourself in the foot repeatedly with an incredibly large and very heavy Swiss Army knife. or You pick up the gun and begin to load it. The gun and your foot begin to grow to huge proportions and the world around you slows down, until the gun fires. It makes a tiny hole, which you don't feel. Assembly Language You crash the OS and overwrite the root disk. The system administrator arrives and shoots you in the foot. After a moment of contemplation, the administrator shoots himself in the foot and then hops around the room rabidly shooting at everyone in sight. or You try to shoot yourself in the foot only to discover you must first reinvent the gun, the bullet, and your foot.or The bullet travels to your foot instantly, but it took you three weeks to load the round and aim the gun.   BCPL You shoot yourself somewhere in the leg -- you can't get any finer resolution than that. Concurrent Euclid You shoot yourself in somebody else's foot.   Motif You spend days writing a UIL description of your foot, the trajectory, the bullet and the intricate scrollwork on the ivory handles of the gun. When you finally get around to pulling the trigger, the gun jams.   Powerbuilder While attempting to load the gun you discover that the LoadGun system function is buggy; as a work around you tape the bullet to the outside of the gun and unsuccessfully attempt to fire it with a nail. In frustration you club your foot with the butt of the gun and explain to your client that this approximates the functionality of shooting yourself in the foot and that the next version of Powerbuilder will fix it.   Standard ML By the time you get your code to typecheck, you're using a shoot to foot yourself in the gun.   MUMPS You shoot 583149 AK-47 teflon-tipped, hollow-point, armour-piercing bullets into even-numbered toes on odd-numbered feet of everyone in the building -- with one line of code. Three weeks later you shoot yourself in the head rather than try to modify that line.   Java You locate the Gun class, but discover that the Bullet class is abstract, so you extend it and write the missing part of the implementation. Then you implement the ShootAble interface for your foot, and recompile the Foot class. The interface lets the bullet call the doDamage method on the Foot, so the Foot can damage itself in the most effective way. Now you run the program, and call the doShoot method on the instance of the Gun class. First the Gun creates an instance of Bullet, which calls the doFire method on the Gun. The Gun calls the hit(Bullet) method on the Foot, and the instance of Bullet is passed to the Foot. But this causes an IllegalHitByBullet exception to be thrown, and you die.   Unix You shoot yourself in the foot or % ls foot.c foot.h foot.o toe.c toe.o % rm * .o rm: .o: No such file or directory % ls %   370 JCL (alternative) You shoot yourself in the head just thinking about it.   DOS JCL You first find the building you're in in the phone book, then find your office number in the corporate phone book. Then you have to write this down, then describe, in cubits, your exact location, in relation to the door (right hand side thereof). Then you need to write down the location of the gun (loading it is a proprietary utility), then you load it, and the COBOL program, and run them, and, with luck, it may be run tonight.   VMS   $ MOUNT/DENSITY=.45/LABEL=BULLET/MESSAGE="BYE" BULLET::BULLET$GUN SYS$BULLET $ SET GUN/LOAD/SAFETY=OFF/SIGHT=NONE/HAND=LEFT/CHAMBER=1/ACTION=AUTOMATIC/ LOG/ALL/FULL SYS$GUN_3$DUA3:[000000]GUN.GNU $ SHOOT/LOG/AUTO SYS$GUN SYS$SYSTEM:[FOOT]FOOT.FOOT   %DCL-W-ACTIMAGE, error activating image GUN -CLI-E-IMGNAME, image file $3$DUA240:[GUN]GUN.EXE;1 -IMGACT-F-NOTNATIVE, image is not an OpenVMS Alpha AXP image or %SYS-F-FTSHT, foot shot (fifty lines of traceback omitted) sh,csh, etc You can't remember the syntax for anything, so you spend five hours reading manual pages, then your foot falls asleep. You shoot the computer and switch to C.   Apple System 7 Double click the gun icon and a window giving a selection for guns, target areas, plus balloon help with medical remedies, and assorted sound effects. Click "shoot" button and a small bomb appears with note "Error of Type 1 has occurred."   Windows 3.1 Double click the gun icon and wait. Eventually a window opens giving a selection for guns, target areas, plus balloon help with medical remedies, and assorted sound effects. Click "shoot" button and a small box appears with note "Unable to open Shoot.dll, check that path is correct."   Windows 95 Your gun is not compatible with this OS and you must buy an upgrade and install it before you can continue. Then you will be informed that you don't have enough memory.   CP/M I remember when shooting yourself in the foot with a BB gun was a big deal.   DOS You finally found the gun, but can't locate the file with the foot for the life of you.   MSDOS You shoot yourself in the foot, but can unshoot yourself with add-on software.   Access You try to point the gun at your foot, but it shoots holes in all your Borland distribution diskettes instead.   Paradox Not only can you shoot yourself in the foot, your users can too.   dBase You squeeze the trigger, but the bullet moves so slowly that by the time your foot feels the pain, you've forgotten why you shot yourself anyway. or You buy a gun. Bullets are only available from another company and are promised to work so you buy them. Then you find out that the next version of the gun is the one scheduled to actually shoot bullets.   DBase IV, V1.0 You pull the trigger, but it turns out that the gun was a poorly designed hand grenade and the whole building blows up.   SQL You cut your foot off, send it out to a service bureau and when it returns, it has a hole in it but will no longer fit the attachment at the end of your leg. or Insert into Foot Select Bullet >From Gun.Hand Where Chamber = 'LOADED' And Trigger = 'PULLED'   Clipper You grab a bullet, get ready to insert it in the gun so that you can shoot yourself in the foot and discover that the gun that the bullets fits has not yet been built, but should be arriving in the mail _REAL_SOON_NOW_. Oracle The menus for coding foot_shooting have not been implemented yet and you can't do foot shooting in SQL.   English You put your foot in your mouth, then bite it off. (For those who don't know, English is a McDonnell Douglas/PICK query language which allegedly requires 110% of system resources to run happily.) Revelation [an implementation of the PICK Operating System] You'll be able to shoot yourself in the foot just as soon as you figure out what all these bullets are for.   FlagShip Starting at the top of your head, you aim the gun at yourself repeatedly until, half an hour later, the gun is finally pointing at your foot and you pull the trigger. A new foot with a hole in it appears but you can't work out how to get rid of the old one and your gun doesn't work anymore.   FidoNet You put your foot in your mouth, then echo it internationally.   PicoSpan [a UNIX-based computer conferencing system] You can't shoot yourself in the foot because you're not a host. or (host variation) Whenever you shoot yourself in the foot, someone opens a topic in policy about it.   Internet You put your foot in your mouth, shoot it, then spam the bullet so that everybody gets shot in the foot.   troff rmtroff -ms -Hdrwp | lpr -Pwp2 & .*place bullet in footer .B .NR FT +3i .in 4 .bu Shoot! .br .sp .in -4 .br .bp NR HD -2i .*   Genetic Algorithms You create 10,000 strings describing the best way to shoot yourself in the foot. By the time the program produces the optimal solution, humans have evolved wings and the problem is moot.   CSP (Communicating Sequential Processes) You only fail to shoot everything that isn't your foot.   MS-SQL Server MS-SQL Server’s gun comes pre-loaded with an unlimited supply of Teflon coated bullets, and it only has two discernible features: the muzzle and the trigger. If that wasn't enough, MS-SQL Server also puts the gun in your hand, applies local anesthetic to the skin of your forefinger and stitches it to the gun's trigger. Meanwhile, another process has set up a spinal block to numb your lower body. It will then proceeded to surgically remove your foot, cryogenically freeze it for preservation, and attach it to the muzzle of the gun so that no matter where you aim, you will shoot your foot. In order to avoid shooting yourself in the foot, you need to unstitch your trigger finger, remove your foot from the muzzle of the gun, and have it surgically reattached. Then you probably want to get some crutches and go out to buy a book on SQL Server Performance Tuning.   Sybase Sybase's gun requires assembly, and you need to go out and purchase your own clip and bullets to load the gun. Assembly is complicated by the fact that Sybase has hidden the gun behind a big stack of reference manuals, but it hasn't told you where that stack is. While you were off finding the gun, assembling it, buying bullets, etc., Sybase was also busy surgically removing your foot and cryogenically freezing it for preservation. Instead of attaching it to the muzzle of the gun, though, it packed your foot on dry ice and sent it UPS-Ground to an unnamed hookah bar somewhere in the middle east. In order to shoot your foot, you must modify your gun with a GPS system for targeting and hire some guy named "Indy" to find the hookah bar and wire the coordinates back to you. By this time, you've probably become so daunted at the tasks stand between you and shooting your foot that you hire a guy who's read all the books on Sybase to help you shoot your foot. If you're lucky, he'll be smart enough both to find your foot and to stop you from shooting it.   Magic software You spend 1 week looking up the correct syntax for GUN. When you find it, you realise that GUN will not let you shoot in your own foot. It will allow you to shoot almost anything but your foot. You then decide to build your own gun. You can't use the standard barrel since this will only allow for standard bullets, which will not fire if the barrel is pointed at your foot. After four weeks, you have created your own custom gun. It blows up in your hand without warning, because you failed to initialise the safety catch and it doesn't know whether the initial state is "0", 0, NULL, "ZERO", 0.0, 0,0, "0.0", or "0,00". You fix the problem with your remaining hand by nesting 12 safety catches, and then decide to build the gun without safety catch. You then shoot the management and retire to a happy life where you code in languages that will allow you to shoot your foot in under 10 days.FirefoxLets you shoot yourself in as many feet as you'd like, while using multiple great addons! IEA moving target in terms of standard ammunition size and doesn't always work properly with non-Microsoft ammunition, so sometimes you shoot something other than your foot. However, it's the corporate world's standard foot-shooting apparatus. Hackers seem to enjoy rigging websites up to trigger cascading foot-shooting failures. Windows 98 About the same as Windows 95 in terms of overall bullet capacity and triggering mechanisms. Includes updated DirectShot API. A new version was released later on to support USB guns, Windows 98 SE.WPF:You get your baseball glove and a ball and you head out to your backyard, where you throw balls to your pitchback. Then your unkempt-haired-cargo-shorts-and-sandals-with-white-socks-wearing neighbor uses XAML to sculpt your arm into a gun, the ball into a bullet and the pitchback into your foot. By now, however, only the neighbor can get it to work and he's only around from 6:30 PM - 3:30 AM. LOGO: You very carefully lay out the trajectory of the bullet. Then you start the gun, which fires very slowly. You walk precisely to the point where the bullet will travel and wait, but just before it gets to you, your class time is up and one of the other kids has already used the system to hack into Sony's PS3 network. Flash: Someone has designed a beautiful-looking gun that anyone can shoot their feet with for free. It weighs six hundred pounds. All kinds of people are shooting themselves in the feet, and sending the link to everyone else so that they can too. That is, except for the criminals, who are all stealing iOS devices that the gun won't work with.APL: Its (mostly) all greek to me. Lisp: Place ((gun in ((hand sight (foot then shoot))))) (Lots of Insipid Stupid Parentheses)Apple OS/X and iOS Once a year, Steve Jobs returns from sick leave to tell millions of unwavering fans how they will be able to shoot themselves in the foot differently this year. They retweet and blog about it ad nauseam, and wait in line to be the first to experience "shoot different".Windows ME Usually fails, even at shooting you in the foot. Yo dawg, I heard you like shooting yourself in the foot. So I put a gun in your gun, so you can shoot yourself in the foot while you shoot yourself in the foot. (Okay, I'm not especially proud of this joke.) Windows 2000 Now you really do have to log in, before you are allowed to shoot yourself in the foot.Windows XPYou thought you learned your lesson: Don't use Windows ME. Then, along came this new creature, built on top of Windows NT! So you spend the next couple days installing antivirus software, patches and service packs, just so you can get that driver to install, and then proceed to shoot yourself in the foot. Windows Vista Newer! Glossier! Shootier! Windows 7 The bullets come out a lot smoother. Active Directory Each bullet now has an attached Bullet Identifier, and can be uniquely identified. Policies can be applied to dictate fragmentation, and the gun will occasionally have a confusing delay after the trigger has been pulled. PythonYou try to use import foot; foot.shoot() only to realize that's only available in 3.0, to which you can't yet upgrade from 2.7 because of all those extension libs lacking support. Solaris Shoots best when used on SPARC hardware, but still runs the trigger GUI under Java. After weeks of learning the appropriate STOP command to prevent the trigger from automatically being pressed on boot, you think you've got it under control. Then the one time you ever use dtrace, it hits a bug that fires the gun. MySQL The feature that allows you to shoot yourself in the foot has been in development for about 6 years, and they are adding it into the next version, which is coming out REAL SOON NOW, promise! But you can always check it out of source control and try it yourself (just not in any environment where data integrity is important because it will probably explode.) PostgreSQLAllows you to have a smug look on your face while you shoot yourself in the foot, because those MySQL guys STILL don't have that feature. NoSQL Barrel? Who needs a barrel? Just put the bullet on your foot, and strike it with a hammer. See? It's so much simpler and more efficient that way. You can even strike multiple bullets in one swing if you swing with a good enough arc, because hammers are easy to use. Getting them to synchronize is a little difficult, though.Eclipse There are about a dozen different packages for shooting yourself in the foot, with weird interdependencies on outdated components. Once you finally navigate the morass and get one installed, you then have something to look at while you shoot yourself in the foot with that package: You can watch the screen redraw.Outlook Makes it really easy to let everyone know you shot yourself in the foot!Shooting yourself in the foot using delegates.You really need to shoot yourself in the foot but you hate firearms (you don't want any dependency on the specifics of shooting) so you delegate it to somebody else. You don't care how it is done as long is shooting your foot. You can do it asynchronously in case you know you may faint so you are called back/slapped in the face by your shooter/friend (or background worker) when everything is done.C#You prepare the gun and the bullet, carefully modeling all of the physics of a bullet traveling through a foot. Just before you're about to pull the trigger, you stumble on System.Windows.BodyParts.Foot.ShootAt(System.Windows.Firearms.IGun gun) in the extended framework, realize you just wasted the entire afternoon, and shoot yourself in the head.PHP<?phprequire("foot_safety_check.php");?><!DOCTYPE HTML><html><head> <!--Lower!--><title>Shooting me in the foot</title></head> <body> <!--LOWER!!!--><leg> <!--OK, I made this one up...--><footer><?php echo (dungSift($_SERVER['HTTP_USER_AGENT'], "ie"))?("Your foot is safe, but you might want to wear a hard hat!"):("<div class=\"shot\">BANG!</div>"); ?></footer></leg> </body> </html>

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  • CodePlex Daily Summary for Sunday, November 28, 2010

    CodePlex Daily Summary for Sunday, November 28, 2010Popular ReleasesMDownloader: MDownloader-0.15.25.7002: Fixed updater Fixed FileServe Fixed LetItBitNotepad.NET: Notepad.NET 0.7 Preview 1: Whats New?* Optimized Code Generation: Which means it will run significantly faster. * Preview of Syntax Highlighting: Only VB.NET highlighting is supported, C# and Ruby will come in Preview 2. * Improved Editing Updates (when the line number, etc updates) to be more graceful. * Recent Documents works! * Images can be inserted but they're extremely large. Known Bugs* The Update Process hangs: This is a bug apparently spawning since 0.5. It will be fixed in Preview 2. Until then, perform a fr...Flickr Schedulr: Schedulr v2.2.3984: This is v2.2 of Flickr Schedulr, a Windows desktop application that automatically uploads pictures and videos to Flickr based on a schedule (e.g. to post a new picture every day at a certain time). What's new in this release? Videos are now supported as well. The application can now automatically add pictures to the queue when it starts up, from specific monitored folders. Sets and Groups can now be displayed as text only (without icons) to speed up the application. Fixed issue that ta...Cropper: 1.9.4: Mostly fixes for issues with a few feature requests. Fixed Issues 2730 & 3638 & 14467 11044 11447 11448 11449 14665 Implemented Features 6123 11581PFC: PFC for PB 11.5: This is just a migration from the 11.0 code. No changes have been made yet (and they are needed) for it to work properly with 11.5.PDF Rider: PDF Rider 0.5: This release does not add any new feature for pdf manipulation, but enables automatic updates checking, so it is reccomended to install it in order to stay updated with next releases. Prerequisites * Microsoft Windows Operating Systems (XP - Vista - 7) * Microsoft .NET Framework 3.5 runtime * A PDF rendering software (i.e. Adobe Reader) that can be opened inside Internet Explorer. Installation instructionsChoose one of the following methods: 1. Download and run the "pdfRider0...XamlQuery/WPF - The Write Less, Do More, WPF Library: XamlQuery-WPF v1.2 (Runtime, Source): This is the first release of popular XamlQuery library for WPF. XamlQuery has already gained recognition among Silverlight developers.Math.NET Numerics: Beta 1: First beta of Math.NET Numerics. Only contains the managed linear algebra provider. Beta 2 will include the native linear algebra providers along with better documentation and examples.Minecraft GPS: Minecraft GPS 1.1: 1.1 Release New Features Compass! New style. Set opacity on main window to allow overlay of Minecraft.Microsoft All-In-One Code Framework: Visual Studio 2010 Code Samples 2010-11-25: Code samples for Visual Studio 2010Wii Backup Fusion: Wii Backup Fusion 0.8.5 Beta: - WBFS repair (default) options fixed - Transfer to image fixed - Settings ui widget names fixed - Some little bug fixes You need to reset the settings! Delete WiiBaFu's config file or registry entries on windows: Linux: ~/.config/WiiBaFu/wiibafu.conf Windows: HKEY_CURRENT_USER\Software\WiiBaFu\wiibafu Mac OS X: ~/Library/Preferences/com.wiibafu.wiibafu.plist Caution: This is a BETA version! Errors, crashes and data loss not impossible! Use in test environments only, not on productive syste...Minemapper: Minemapper v0.1.3: Added process count and world size calculation progress to the status bar. Added View->'Status Bar' menu item to show/hide the status bar. Status bar is automatically shown when loading a world. Added a prompt, when loading a world, to use or clear cached images.Sexy Select: sexy select v0.4: Changes in v0.4 Added method : elements. This returns all the option elements that are currently added to the select list Added method : selectOption. This method accepts two values, the element to be modified and the selected state. (true/false)Deep Zoom for WPF: First Release: This first release of the Deep Zoom control has the same source code, binaries and demos as the CodeProject article (http://www.codeproject.com/KB/WPF/DeepZoom.aspx).BlogEngine.NET: BlogEngine.NET 2.0 RC: This is a Release Candidate version for BlogEngine.NET 2.0. The most current, stable version of BlogEngine.NET is version 1.6. Find out more about the BlogEngine.NET 2.0 RC here. If you want to extend or modify BlogEngine.NET, you should download the source code. To get started, be sure to check out our installation documentation and the installation screencast. If you are upgrading from a previous version, please take a look at the Upgrading to BlogEngine.NET 2.0 instructions. As this ...NodeXL: Network Overview, Discovery and Exploration for Excel: NodeXL Excel Template, version 1.0.1.156: The NodeXL Excel template displays a network graph using edge and vertex lists stored in an Excel 2007 or Excel 2010 workbook. What's NewThis release adds a feature for aggregating the overall metrics in a folder full of NodeXL workbooks, adds geographical coordinates to the Twitter import features, and fixes a memory-related bug. See the Complete NodeXL Release History for details. Please Note: There is a new option in the setup program to install for "Just Me" or "Everyone." Most people...VFPX: FoxBarcode v.0.11: FoxBarcode v.0.11 - Released 2010.11.22 FoxBarcode is a 100% Visual FoxPro class that provides a tool for generating images with different bar code symbologies to be used in VFP forms and reports, or exported to other applications. Its use and distribution is free for all Visual FoxPro Community. Whats is new? Added a third parameter to the BarcodeImage() method Fixed some minor bugs History FoxBarcode v.0.10 - Released 2010.11.19 - 85 Downloads Project page: FoxBarcodeDotNetAge -a lightweight Mvc jQuery CMS: DotNetAge 1.1.0.5: What is new in DotNetAge 1.1.0.5 ?Document Library features and template added. Resolve issues of templates Improving publishing service performance Opml support added. What is new in DotNetAge 1.1 ? D.N.A Core updatesImprove runtime performance , more stabilize. The DNA core objects model added. Personalization features added that allows users create the personal website, manage their resources, store personal data DynamicUIFixed the PageManager could not move page node bug. ...ASP.NET MVC Project Awesome (jQuery Ajax helpers): 1.3.1 and demos: A rich set of helpers (controls) that you can use to build highly responsive and interactive Ajax-enabled Web applications. These helpers include Autocomplete, AjaxDropdown, Lookup, Confirm Dialog, Popup Form and Pager tested on mozilla, safari, chrome, opera, ie 9b/8/7/6DotSpatial: DotSpatial 11-21-2010: This release introduces the following Fixed bugs related to dispose, which caused issues when reordering layers in the legend Fixed bugs related to assigning categories where NULL values are in the fields New fast-acting resize using a bitmap "prediction" of what the final resize content will look like. ImageData.ReadBlock, ImageData.WriteBlock These allow direct file access for reading or writing a rectangular window. Bitmaps are used for holding the values. Removed the need to stor...New ProjectsAC: Just a simple AC ProjectAvailability Manager Project (CMPE290): Availability Manager Project (CMPE290)BCLExtensions: BCLExtensions is an extension method library for .NET 3.5 or higher which offers various extension methods for classes in the .NET Base Class Library (BCL)Command Browser 2.0 for Visual Studio: The Command Browser is a visual studio add-in that Lets you browse, and execute Visual Studio commands on the fly. It’s very handy for people that don’t tend to use bindings on daily basis and simply wants to learn new commands out of interest.EDM And T4: Generate a WCF Service from your edmxEmperor of the Multiverse: Szoftverarchitekturak rocks :)KINECT CALL: Kinect CallMultiSafepay for nopCommerce: This is MultiSafepay shop plugin voor nopCommerce. The current version supported is nopCommerce 1.60.MyGadgebydeleted: MyGadgebydeletedNHashcash: NHashcash is a .NET implementation of the Hashcash mechanism for paying for e-mail with burnt CPU cycles.OhYeah!: WP7 Note Demo ApplicationOMax - Online Market and Exchange for Real Estate: OMax Project - Online Real Estate Management System OMax stands for Online Market and eXchange and is a Real Estate management system focusing on both individuals (brokers, agents) and organizations (real estate companies) looking for online property management solutions.Opus - Silverlight UI Framework: The opus framework provides a simple way for creating UIs for Silverlight by leveraging your current MVVM structure. Outliner, the edge detection utility: Outliner is a vectorizer of the edges in the raster pictures. The new edge detection algorithm is used. It is developed in Visual C++ 2010 Express Edition, using WinAPI and STL.SharpDropBox Client for .NET: SharpDropBox Client is a DropBox client for (at first) WP7. It caches files/directories in ISO storage, and also uses Sterling DB to metadata info so that it can easily do hash checks against DropBox making it download only when there are changes. It can also be used offline.SicunSimpleDiary: ???????(????)Silverlight Navigation With Caliburn.Micro: Bring the power of the Cabliurn.Micro MVVM framework to Siliverlight 4 navigation applications. This sample application for CM shows how it can be used to create MVVM friendly Navigation applications which formerly required a view-first approach. SilverTrace - a tracer and logger for Silverlight applications: SilverTrace - a tracer and logger for Silverlight applications.StackDeck: StackDeck is a StackOverflow analysis tool written in WPFSVNHelper -- a small clean tool for visual studio: A small tool that used to clean your bin direcotry and temporary directory for the whole solutions. I usually use it before commit soure to a SVN Server. System.Xml.Serialization: Expressions.Compiler is a lightweight xml serialization framework. It is an addition to the standart .NET XML serialization. It is designed to support out-of-the-box features: * interface-driven Xml serialization * class-driven Xml serialization * runtime serializationVoXign: - Proposer une formation introductive à la langue des signes, en e-Learning. - autonomie de gestion de l’emploi du temps, du rythme - apprentissage d’un lexique de « première nécessité » - introduction à la culture sourde et approche des spécificités linguistiques de la LSF Weyland: A .NET metaprogramming framework.

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  • Extending Programming Languages

    - by chpwn
    (Since I just posted this in another question, but my browser had to be annoying and submit it without content first, here it is again:) I'm a fan of clean code. I like my languages to be able to express what I'm trying to do, but I like the syntax to mirror that too. For example, I work on a lot of programs in Objective-C for jailbroken iPhones, which patch other code using the method_setImplementation() function of the runtime. Or, in pyobjc, I have to use the syntax UIView.initWithFrame_(), which is also pretty awful and unreadable with the way the method names are structured. In both cases, the language does not support this in syntax. I've found three basic ways that this is done: Insane macros. Take a look at this "CaptainHook", it does what I'm looking for in a usable way, but it isn't quite clean and is a major hack. There's also "Logos", which implements a very nice syntax, but is written in Perl parsing my code with a ton of regular expressions. This scares me. I like the idea of adding a %hook ClassName, but not by using regular expressions to parse C or Objective-C. Finally, there is Cycript. This is an extension to JavaScript which interfaces with the Objective-C runtime and allows you to use Objective-C style code in your JavaScript, and inject that into other processes. This is likely the cleanest as it actually uses a parser for the JavaScript, but I'm not a huge fan of that language in general. Basically, this is a two part question. Should, and how should, I create an extension to Python and Objective-C to allow me to do this? Is it worth writing a parser for my language to transform the syntax into something nicer, if it is only in a very specialized niche like this? Should I just live with the horrible syntax of the default Objective-C hooking or pyobjc?

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  • What are some good/reputable/widely-used libraries written in VB.NET?

    - by Dan Tao
    Generally speaking, when VB.NET and C# are compared, there is a lot of strong support for C#, accompanied by some bashing of VB.NET until a respected developer comes along and acts as The Voice Of Reason, pointing out that while VB prior to VB.NET had its fair share of issues, VB.NET is really a very strong, fully OOP language that is, feature-wise, right about on par with C# (with the exception of certain things like a full-bodied lamba syntax [pre-VB10] or the yield keyword, as many C# faithfuls are quick to point out). I myself, having written plenty of code in both VB.NET and C#, fall squarely in the "I prefer C#, but don't consider VB.NET any less of a language" camp. However, one thing I have noticed is that when it comes to respected and/or widely-used libraries for .NET, everyting is written in C#. Or at least that's been my impression. This strikes me as a little strange because, aside from the abovementioned sprinkling of nice features (in particular the yield keyword), I tend to view the VB.NET/C# divide as primarily a matter of personal taste. Obviously, plenty of developers prefer C#. But I personally know some developers (good ones) who prefer VB.NET, which would lead me to suspect that surely some libraries (good ones) would be written in VB.NET. They must be out there, and I just haven't found them. What are some good libraries that've been written in VB.NET? The best would be open source, as that would allow interested developers to take a look at some good VB.NET code and see how effective the language can be when used properly. But I'd be interested to know about any libraries at all, particularly reputable ones.

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  • MySQL2 Ruby gem will not Install 10.6

    - by Kish
    I know this has been asked several times, but I searched and I tried many different things and nothing worked. ERROR: Error installing mysql2: ERROR: Failed to build gem native extension. /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/bin/ruby extconf.rb checking for rb_thread_blocking_region()... yes checking for mysql.h... yes checking for errmsg.h... yes checking for mysqld_error.h... yes creating Makefile make gcc -I. -I/Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/x86_64-darwin10.6.0 -I/Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/backward -I/Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1 -I. -DHAVE_RB_THREAD_BLOCKING_REGION -DHAVE_MYSQL_H -DHAVE_ERRMSG_H -DHAVE_MYSQLD_ERROR_H -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -I/usr/local/mysql/include -Os -g -fno-common -fno-strict-aliasing -arch i386 -fno-common -O3 -ggdb -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-missing-field-initializers -Wshorten-64-to-32 -Wno-long-long -fno-common -pipe -Wall -funroll-loops -o client.o -c client.c In file included from /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby.h:32, from ./mysql2_ext.h:4, from client.c:1: /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/ruby.h:108: error: size of array ‘ruby_check_sizeof_long’ is negative /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/ruby.h:112: error: size of array ‘ruby_check_sizeof_voidp’ is negative In file included from /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/intern.h:29, from /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/ruby.h:1327, from /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby.h:32, from ./mysql2_ext.h:4, from client.c:1: /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/st.h:69: error: size of array ‘st_check_for_sizeof_st_index_t’ is negative make: *** [client.o] Error 1 Gem files will remain installed in /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/gems/1.9.1/gems/mysql2-0.2.6 for inspection. Results logged to /Users/kishinmanglani/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/gems/1.9.1/gems/mysql2-0.2.6/ext/mysql2/gem_make.out

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  • C# - Fill a combo box with a DataTable

    - by MrG
    I'm used to work with Java where large amounts of examples are available. For various reasons I had to switch to C# and trying to do the following in SharpDevelop: // Form has a menu containing a combobox added via SharpDevelop's GUI // --- Variables languages = new string[2]; languages[0] = "English"; languages[1] = "German"; DataSet myDataSet = new DataSet(); // --- Preparation DataTable lTable = new DataTable("Lang"); DataColumn lName = new DataColumn("Language", typeof(string)); lTable.Columns.Add( lName ); for( int i=0; i<languages.Length; i++ ) { DataRow lLang = lTable.NewRow(); lLang["Language"] = languages[i]; lTable.Rows.Add(lLang); } myDataSet.Tables.Add(lTable); // --- Handling the combobox mnuActionLanguage.ComboBox.DataSource = myDataSet.Tables["Lang"].DefaultView; mnuActionLanguage.ComboBox.DisplayMember = "Language"; One would assume to see some values in the dropdown, but it's empty. Please tell me what I'm doing wrong ;( EDIT: mnuActionLanguage.ComboBox.DataBind() is what I also found on the net, but it doesn't work in my case. SOLUTION mnuActionLanguage.ComboBox.BindingContext = this.BindingContext; at the end solved the problem!

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