Search Results

Search found 4493 results on 180 pages for 'operator keyword'.

Page 150/180 | < Previous Page | 146 147 148 149 150 151 152 153 154 155 156 157  | Next Page >

  • 45 minutes to talk about C# [closed]

    - by Philip
    I have the opportunity to give a 45 minute talk on C# in the theory of programming languages class I'm taking. The college teaches Java almost exclusively, so that's what all the students are most familiar with. (There's a little C, assembly, Prolog and LISP as well.) I decide what to talk about. It seems to me the best approach is to focus on a few of the big, obvious differences between C# and Java. I don't intend it to be a recommendation to use C# -- there are reasons to use each, mostly because of their ecosystems. So I want to focus on C# as a language. I don't want to go too fast and end up listing a whole bunch of features without showing their usefulness. My current plan is this: Functions as first class objects. This is, in my opinion, one of the biggest differences between C# and Java. The professor briefly mentioned this notion and showed a LISP example, but many of the students have probably never used it. I can show real world examples where it's made my code more readable. Lambda expressions as concise syntax for anonymous functions. Obviously with examples to show how this is useful. The real hit-home examples will be at the end when it's combined with the rest. I don't see an advantage to first showing the old delegate syntax and then replacing it with lambdas -- most of us won't have ever seen delegates anyway so it would just be confusing. The yield keyword and how it's different from returning an array. I have the impression that a lot of C# developers aren't familiar with how to use this. It will likely be very foreign to Java developers. I have some examples from my own work where it was really useful, such as iterating over a tree traversal, or iterating over neighbors in a graph where the neighbors aren't stored in memory. In both cases, doing it in Java would likely mean returning a complete list -- with yield I can stop iterating if I find what I want early on, without using memory for superfluous lists or arrays. Extension methods as a way to write implementation on interfaces. We'll all be familiar with how interfaces don't allow method implementation, and how this leads to code duplication. I'll show a specific example of this and how the extension method can solve the problem. Demonstrate how the above can be combined by implementing some simple Linq methods and using them. Where, Select, First, maybe more depending on how much time is left. Ideas on which ones might 'hit home' the best? There are other things I could talk about such as generics, value types, properties and more. I haven't yet though of good ways to incorporate these. In the case of generics and value types, the advantages might not be obvious or as relevant. Properties are obviously useful, particularly since we're taught strict JavaBeans here, but I don't know if I could integrate it with the "path to Linq" discussion above without it feeling tacked on. So I'm looking for thoughts on how to talk about C#, and what to talk about. Even minor details. I'm sure there are more experienced C# developers than me here who have good insight about what's really important in the language, and what would miss the point.

    Read the article

  • Math with Timestamp

    - by Knut Vatsendvik
    table.sql { border-width: 1px; border-spacing: 2px; border-style: dashed; border-color: #0023ff; border-collapse: separate; background-color: white; } table.sql th { border-width: 1px; padding: 1px; border-style: none; border-color: gray; background-color: white; -moz-border-radius: 0px 0px 0px 0px; } table.sql td { border-width: 1px; padding: 3px; border-style: none; border-color: gray; background-color: white; -moz-border-radius: 0px 0px 0px 0px; } .sql-keyword { color: #0000cd; background-color: inherit; } .sql-result { color: #458b74; background-color: inherit; } Got this little SQL quiz from a colleague.  How to add or subtract exactly 1 second from a Timestamp?  Sounded simple enough at first blink, but was a bit trickier than expected. If the data type had been a Date, we knew that we could add or subtract days, minutes or seconds using + or – sysdate + 1 to add one day sysdate - (1 / 24) to subtract one hour sysdate + (1 / 86400) to add one second Would the same arithmetic work with Timestamp as with Date? Let’s test it out with the following query SELECT   systimestamp , systimestamp + (1 / 86400) FROM dual; ---------- 03.05.2010 22.11.50,240887 +02:00 03.05.2010 The first result line shows us the system time down to fractions of seconds. The second result line shows the result as Date (as used for date calculation) meaning now that the granularity is reduced down to a second.   By using the PL/SQL dump() function, we can confirm this with the following query SELECT   dump(systimestamp) , dump(systimestamp + (1 / 86400)) FROM dual; ---------- Typ=188 Len=20: 218,7,5,4,8,53,9,0,200,46,89,20,2,0,5,0,0,0,0,0 Typ=13 Len=8: 218,7,5,4,10,53,10,0 Where typ=13 is a runtime representation for Date. So how can we increase the precision to include fractions of second? After investigating it a bit, we found out that the interval data type INTERVAL DAY TO SECOND could be used with the result of addition or subtraction being a Timestamp. Let’s try again our first query again, now using the interval data type. SELECT systimestamp,    systimestamp + INTERVAL '0 00:00:01.0' DAY TO SECOND(1) FROM dual; ---------- 03.05.2010 22.58.32,723659000 +02:00 03.05.2010 22.58.33,723659000 +02:00 Yes, it worked! To finish the story, here is one example showing how to specify an interval of 2 days, 6 hours, 30 minutes, 4 seconds and 111 thousands of a second. INTERVAL ‘2 6:30:4.111’ DAY TO SECOND(3)

    Read the article

  • Default Parameters vs Method Overloading

    - by João Angelo
    With default parameters introduced in C# 4.0 one might be tempted to abandon the old approach of providing method overloads to simulate default parameters. However, you must take in consideration that both techniques are not interchangeable since they show different behaviors in certain scenarios. For me the most relevant difference is that default parameters are a compile time feature while method overloading is a runtime feature. To illustrate these concepts let’s take a look at a complete, although a bit long, example. What you need to retain from the example is that static method Foo uses method overloading while static method Bar uses C# 4.0 default parameters. static void CreateCallerAssembly(string name) { // Caller class - Invokes Example.Foo() and Example.Bar() string callerCode = String.Concat( "using System;", "public class Caller", "{", " public void Print()", " {", " Console.WriteLine(Example.Foo());", " Console.WriteLine(Example.Bar());", " }", "}"); var parameters = new CompilerParameters(new[] { "system.dll", "Common.dll" }, name); new CSharpCodeProvider().CompileAssemblyFromSource(parameters, callerCode); } static void Main() { // Example class - Foo uses overloading while Bar uses C# 4.0 default parameters string exampleCode = String.Concat( "using System;", "public class Example", "{{", " public static string Foo() {{ return Foo(\"{0}\"); }}", " public static string Foo(string key) {{ return \"FOO-\" + key; }}", " public static string Bar(string key = \"{0}\") {{ return \"BAR-\" + key; }}", "}}"); var compiler = new CSharpCodeProvider(); var parameters = new CompilerParameters(new[] { "system.dll" }, "Common.dll"); // Build Common.dll with default value of "V1" compiler.CompileAssemblyFromSource(parameters, String.Format(exampleCode, "V1")); // Caller1 built against Common.dll that uses a default of "V1" CreateCallerAssembly("Caller1.dll"); // Rebuild Common.dll with default value of "V2" compiler.CompileAssemblyFromSource(parameters, String.Format(exampleCode, "V2")); // Caller2 built against Common.dll that uses a default of "V2" CreateCallerAssembly("Caller2.dll"); dynamic caller1 = Assembly.LoadFrom("Caller1.dll").CreateInstance("Caller"); dynamic caller2 = Assembly.LoadFrom("Caller2.dll").CreateInstance("Caller"); Console.WriteLine("Caller1.dll:"); caller1.Print(); Console.WriteLine("Caller2.dll:"); caller2.Print(); } And if you run this code you will get the following output: // Caller1.dll: // FOO-V2 // BAR-V1 // Caller2.dll: // FOO-V2 // BAR-V2 You see that even though Caller1.dll runs against the current Common.dll assembly where method Bar defines a default value of “V2″ the output show us the default value defined at the time Caller1.dll compiled against the first version of Common.dll. This happens because the compiler will copy the current default value to each method call, much in the same way a constant value (const keyword) is copied to a calling assembly and changes to it’s value will only be reflected if you rebuild the calling assembly again. The use of default parameters is also discouraged by Microsoft in public API’s as stated in (CA1026: Default parameters should not be used) code analysis rule.

    Read the article

  • SQL Constraints &ndash; CHECK and NOCHECK

    - by David Turner
    One performance issue i faced at a recent project was with the way that our constraints were being managed, we were using Subsonic as our ORM, and it has a useful tool for generating your ORM code called SubStage – once configured, you can regenerate your DAL code easily based on your database schema, and it can even be integrated into your build as a pre-build event if you want to do this.  SubStage also offers the useful feature of being able to generate DDL scripts for your entire database, and can script your data for you too. The problem came when we decided to use the generate scripts feature to migrate the database onto a test database instance – it turns out that the DDL scripts that it generates include the WITH NOCHECK option, so when we executed them on the test instance, and performed some testing, we found that performance wasn’t as expected. A constraint can be disabled, enabled but not trusted, or enabled and trusted.  When it is disabled, data can be inserted that violates the constraint because it is not being enforced, this is useful for bulk load scenarios where performance is important.  So what does it mean to say that a constraint is trusted or not trusted?  Well this refers to the SQL Server Query Optimizer, and whether it trusts that the constraint is valid.  If it trusts the constraint then it doesn’t check it is valid when executing a query, so the query can be executed much faster. Here is an example base in this article on TechNet, here we create two tables with a Foreign Key constraint between them, and add a single row to each.  We then query the tables: 1 DROP TABLE t2 2 DROP TABLE t1 3 GO 4 5 CREATE TABLE t1(col1 int NOT NULL PRIMARY KEY) 6 CREATE TABLE t2(col1 int NOT NULL) 7 8 ALTER TABLE t2 WITH CHECK ADD CONSTRAINT fk_t2_t1 FOREIGN KEY(col1) 9 REFERENCES t1(col1) 10 11 INSERT INTO t1 VALUES(1) 12 INSERT INTO t2 VALUES(1) 13 GO14 15 SELECT COUNT(*) FROM t2 16 WHERE EXISTS17 (SELECT *18 FROM t1 19 WHERE t1.col1 = t2.col1) This all works fine, and in this scenario the constraint is enabled and trusted.  We can verify this by executing the following SQL to query the ‘is_disabled’ and ‘is_not_trusted’ properties: 1 select name, is_disabled, is_not_trusted from sys.foreign_keys This gives the following result: We can disable the constraint using this SQL: 1 alter table t2 NOCHECK CONSTRAINT fk_t2_t1 And when we query the constraints again, we see that the constraint is disabled and not trusted: So the constraint won’t be enforced and we can insert data into the table t2 that doesn’t match the data in t1, but we don’t want to do this, so we can enable the constraint again using this SQL: 1 alter table t2 CHECK CONSTRAINT fk_t2_t1 But when we query the constraints again, we see that the constraint is enabled, but it is still not trusted: This means that the optimizer will check the constraint each time a query is executed over it, which will impact the performance of the query, and this is definitely not what we want, so we need to make the constraint trusted by the optimizer again.  First we should check that our constraints haven’t been violated, which we can do by running DBCC: 1 DBCC CHECKCONSTRAINTS (t2) Hopefully you see the following message indicating that DBCC completed without finding any violations of your constraint: Having verified that the constraint was not violated while it was disabled, we can simply execute the following SQL:   1 alter table t2 WITH CHECK CHECK CONSTRAINT fk_t2_t1 At first glance this looks like it must be a typo to have the keyword CHECK repeated twice in succession, but it is the correct syntax and when we query the constraints properties, we find that it is now trusted again: To fix our specific problem, we created a script that checked all constraints on our tables, using the following syntax: 1 ALTER TABLE t2 WITH CHECK CHECK CONSTRAINT ALL

    Read the article

  • Is Cloud Security Holding Back Social SaaS?

    - by Mike Stiles
    The true promise of social data co-mingling with enterprise data to influence and inform social marketing (all marketing really) lives in cloud computing. The cloud brings processing power, services, speed and cost savings the likes of which few organizations could ever put into action on their own. So why wouldn’t anyone jump into SaaS (Software as a Service) with both feet? Cloud security. Being concerned about security is proper and healthy. That just means you’re a responsible operator. Whether it’s protecting your customers’ data or trying to stay off the radar of regulatory agencies, you have plenty of reasons to make sure you’re as protected from hacking, theft and loss as you can possibly be. But you also have plenty of reasons to not let security concerns freeze you in your tracks, preventing you from innovating, moving the socially-enabled enterprise forward, and keeping up with competitors who may not be as skittish regarding SaaS technology adoption. Over half of organizations are transferring sensitive or confidential data to the cloud, an increase of 10% over last year. With the roles and responsibilities of CMO’s, CIO’s and other C’s changing, the first thing you should probably determine is who should take point on analyzing cloud software options, providers, and policies. An oft-quoted Ponemon Institute study found 36% of businesses don’t have a cloud security policy at all. So that’s as good a place to start as any. What applications and data are you comfortable housing in the cloud? Do you have a classification system for data that clearly spells out where data types can go and how they can be used? Who, both internally and at the cloud provider, will function as admins? What are the different levels of admin clearance? Will your security policies and procedures sync up with those of your cloud provider? The key is verifiable trust. Trust in cloud security is actually going up. 1/3 of organizations polled say it’s the cloud provider who should be responsible for data protection. And when you look specifically at SaaS providers, that expectation goes up to 60%. 57% “strongly agree” or “agree” there’s more confidence in cloud providers’ ability to protect data. In fact, some businesses bypass the “verifiable” part of verifiable trust. Just over half have no idea what their cloud provider does to protect data. And yet, according to the “Private Cloud Vision vs. Reality” InformationWeek Report, 82% of organizations say security/data privacy are one of the main reasons they’re still holding the public cloud at arm’s length. That’s going to be a tough position to maintain, because just as social is rapidly changing the face of marketing, big data is rapidly changing the face of enterprise IT. Netflix, who’s particularly big on the benefits of the cloud, says, "We're systematically disassembling the corporate IT components." An enterprise can never realize the full power of big data, nor get the full potential value out of it, if it’s unwilling to enable the integrations and dataset connections necessary in the cloud. Because integration is called for to reduce fragmentation, a standardized platform makes a lot of sense. With multiple components crafted to work together, you’re maximizing scalability, optimization, cost effectiveness, and yes security and identity management benefits. You can see how the incentive is there for cloud companies to develop and add ever-improving security features, making cloud computing an eventual far safer bet than traditional IT. @mikestilesPhoto: stock.xchng

    Read the article

  • October in Review

    - by Richard Bingham
    With OpenWorld over October was time to get back to serious work for everyone, including the Fusion Applications Developer Relations team. Don't forget the OpenWorld content is still available, including presentation downloads, for a limited period of time so be sure to grab anything you found useful or take another scan for anything you might have missed. Of all the announcements, the continued evolution of the Oracle Cloud services for extending and integrating with Fusion Applications is increasing in popularity, and certainly the Cloud Marketplace is something we're becoming involved in. More details to follow. Fusion Concepts Last week Vik from our team started the new "Fusion Concepts" series of articles, providing those new to Fusion Applications an explanation of the architectural basics, with the aim to reduce the learning curve and lay the platform for more efficient and effective development. The series begun with an insightful first post on the different schemas that exist in the Fusion Applications database. Look out for upcoming posts on multi-lingual entities, profile options, look-ups and more. New Learning Resources Our YouTube channel continued to expand with more 'how to' videos on using page composer, extending the Simplified UI (aka FUSE), and integrating BI reports and analytics. Also the Oracle Learning Library is now well established as a central resource for knowledge, now with thousands of tutorials, videos, and documents. Of particular note are the great new extensibility-related videos added by the CRM Product Management team, including more on the ever-expanding capabilities of Application Composer. To see some examples of these search using keyword 'customization' or the product 'Sales Cloud'. Finally on learning resources, as Oliver mentioned the Oracle Press book on Fusion Application Customization and Extensibility is now available for pre-order on Amazon (due out 1st Jan). Out And About October also saw us attend the annual Apps Conference held by the UK Oracle User Group in London. Interestingly there was an Applications Transformation stream of sessions and content that included Fusion Applications with all the latest in the Oracle Applications evolution, as always focused around the three tenets of social, mobile, and cloud. Read more in Richard's post-event write up. Other teams around Oracle have also been busy. Angelo from the Platform Technical Services group has done quite a bit of work using web services with Fusion SaaS and has published many interesting findings on his blog. It's definitely recommended reading if you are working on any related integration projects. The middleware-for-applications group has built a new tool called "AppAdvantage" offering an online assessment of your use of Fusion Middleware technologies with Oracle Applications. As the popularity of integrating cloud applications with on-premises systems continued to grow, leveraging existing middleware technologies (and licenses) to support the integration solution is likely to be of paramount importance. Similarly the "Build Enterprise Application Extensions with Ease" section of the related webpage has AppsUX director Killan Evers speaking about customization using the composer tools. Both are useful resources for those just getting started with a move to Fusion Applications. The Oracle A-Team, specialists in middleware technical architecture, always publish superb content via their 'chronicles' site, now with a substantial amount specifically related to Fusion Applications. Click on the Fusion Applications menu on the top right of their homepage to see more. Last month of particular note was an article on customizing the timeout pop-up message that shows to inactive users, providing design-time insight and easy-to-follow steps. Finally if you're looking at using Oracle Middleware and Cloud to tailor and extend your applications then you may also be interested in this new blog post on the roadmap for Oracle SOA and the latest on-demand Cloud Development webcast.

    Read the article

  • 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

    Read the article

  • SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – T-SQL Example – Part 2 of 2

    - by pinaldave
    Yesterday I wrote a real world story of how a friend who thought they have an issue with intrusion or virus whereas the issue was really in the code. I strongly suggest you read my earlier blog post Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – Part 1 of 2 before continuing this blog post as this is second part of the first blog post. Let me reproduce the simple scenario in T-SQL. Building Sample Data USE [TestDB] GO -- Creating Table Products CREATE TABLE [dbo].[Products]( [ProductID] [int] NOT NULL, [ProductDesc] [varchar](50) NOT NULL, CONSTRAINT [PK_Products] PRIMARY KEY CLUSTERED ( [ProductID] ASC )) ON [PRIMARY] GO -- Creating Table ProductDetails CREATE TABLE [dbo].[ProductDetails]( [ProductDetailID] [int] NOT NULL, [ProductID] [int] NOT NULL, [Total] [int] NOT NULL, CONSTRAINT [PK_ProductDetails] PRIMARY KEY CLUSTERED ( [ProductDetailID] ASC )) ON [PRIMARY] GO ALTER TABLE [dbo].[ProductDetails] WITH CHECK ADD CONSTRAINT [FK_ProductDetails_Products] FOREIGN KEY([ProductID]) REFERENCES [dbo].[Products] ([ProductID]) ON UPDATE CASCADE ON DELETE CASCADE GO -- Insert Data into Table USE TestDB GO INSERT INTO Products (ProductID, ProductDesc) SELECT 1, 'Bike' UNION ALL SELECT 2, 'Car' UNION ALL SELECT 3, 'Books' GO INSERT INTO ProductDetails ([ProductDetailID],[ProductID],[Total]) SELECT 1, 1, 200 UNION ALL SELECT 2, 1, 100 UNION ALL SELECT 3, 1, 111 UNION ALL SELECT 4, 2, 200 UNION ALL SELECT 5, 3, 100 UNION ALL SELECT 6, 3, 100 UNION ALL SELECT 7, 3, 200 GO Select Data from Tables -- Selecting Data SELECT * FROM Products SELECT * FROM ProductDetails GO Delete Data from Products Table -- Deleting Data DELETE FROM Products WHERE ProductID = 1 GO Select Data from Tables Again -- Selecting Data SELECT * FROM Products SELECT * FROM ProductDetails GO Clean up Data -- Clean up DROP TABLE ProductDetails DROP TABLE Products GO My friend was confused as there was no delete was firing over ProductsDetails Table still there was a delete happening. The reason was because there is a foreign key created between Products and ProductsDetails Table with the keywords ON DELETE CASCADE. Due to ON DELETE CASCADE whenever is specified when the data from Table A is deleted and if it is referenced in another table using foreign key it will be deleted as well. Workaround 1: Design Changes – 3 Tables Change the design to have more than two tables. Create One Product Mater Table with all the products. It should historically store all the products list in it. No products should be ever removed from it. Add another table called Current Product and it should contain only the table which should be visible in the product catalogue. Another table should be called as ProductHistory table. There should be no use of CASCADE keyword among them. Workaround 2: Design Changes - Column IsVisible You can keep the same two tables. 1) Products and 2) ProductsDetails. Add a column with BIT datatype to it and name it as a IsVisible. Now change your application code to display the catalogue based on this column. There should be no need to delete anything. Workaround 3: Bad Advices (Bad advises begins here) The reason I have said bad advices because these are going to be bad advices for sure. You should make necessary design changes and not use poor workarounds which can damage the system and database integrity further. Here are the examples 1) Do not delete the data – well, this is not a real solution but can give time to implement design changes. 2) Do not have ON CASCADE DELETE – in this case, you will have entry in productsdetails which will have no corresponding product id and later on there will be lots of confusion. 3) Duplicate Data – you can have all the data of the product table move to the product details table and repeat them at each row. Now remove CASCADE code. This will let you delete the product table rows without any issue. There are so many things wrong this suggestion, that I will not even start here. (Bad advises ends here)  Well, did I miss anything? Please help me with your suggestions. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Non use of persisted data

    - by Dave Ballantyne
    Working at a client site, that in itself is good to say, I ran into a set of circumstances that made me ponder, and appreciate, the optimizer engine a bit more. Working on optimizing a stored procedure, I found a piece of code similar to : select BillToAddressID, Rowguid, dbo.udfCleanGuid(rowguid) from sales.salesorderheaderwhere BillToAddressID = 985 A lovely scalar UDF was being used,  in actuality it was used as part of the WHERE clause but simplified here.  Normally I would use an inline table valued function here, but in this case it wasn't a good option. So this seemed like a pretty good case to use a persisted column to improve performance. The supporting index was already defined as create index idxBill on sales.salesorderheader(BillToAddressID) include (rowguid) and the function code is Create Function udfCleanGuid(@GUID uniqueidentifier)returns varchar(255)with schemabindingasbegin Declare @RetStr varchar(255) Select @RetStr=CAST(@Guid as varchar(255)) Select @RetStr=REPLACE(@Retstr,'-','') return @RetStrend Executing the Select statement produced a plan of : Nothing surprising, a seek to find the data and compute scalar to execute the UDF. Lets get optimizing and remove the UDF with a persisted column Alter table sales.salesorderheaderadd CleanedGuid as dbo.udfCleanGuid(rowguid)PERSISTED A subtle change to the SELECT statement… select BillToAddressID,CleanedGuid from sales.salesorderheaderwhere BillToAddressID = 985 and our new optimized plan looks like… Not a lot different from before!  We are using persisted data on our table, where is the lookup to fetch it ?  It didnt happen,  it was recalculated.  Looking at the properties of the relevant Compute Scalar would confirm this ,  but a more graphic example would be shown in the profiler SP:StatementCompleted event. Why did the lookup happen ? Remember the index definition,  it has included the original guid to avoid the lookup.  The optimizer knows this column will be passed into the UDF, run through its logic and decided that to recalculate is cheaper than the lookup.  That may or may not be the case in actuality,  the optimizer has no idea of the real cost of a scalar udf.  IMO the default cost of a scalar UDF should be seen as a lot higher than it is, since they are invariably higher. Knowing this, how do we avoid the function call?  Dropping the guid from the index is not an option, there may be other code reliant on it.   We are left with only one real option,  add the persisted column into the index. drop index Sales.SalesOrderHeader.idxBillgocreate index idxBill on sales.salesorderheader(BillToAddressID) include (rowguid,cleanedguid) Now if we repeat the statement select BillToAddressID,CleanedGuid from sales.salesorderheaderwhere BillToAddressID = 985 We still have a compute scalar operator, but this time it wasnt used to recalculate the persisted data.  This can be confirmed with profiler again. The takeaway here is,  just because you have persisted data dont automatically assumed that it is being used.

    Read the article

  • Consumer Oriented Search In Oracle Endeca Information Discovery – Part 1

    - by Bob Zurek
    Information Discovery, a core capability of Oracle Endeca Information Discovery, enables business users to rapidly search, discover and navigate through a wide variety of big data including structured, unstructured and semi-structured data. One of the key capabilities, among many, that differentiate our solution from others in the Information Discovery market is our deep support for search across this growing amount of varied big data. Our method and approach is very different than classic simple keyword search that is found in may information discovery solutions. In this first part of a series on the topic of search, I will walk you through many of the key capabilities that go beyond the simple search box that you might experience in products where search was clearly an afterthought or attempt to catch up to our core capabilities in this area. Lets explore. The core data management solution of Oracle Endeca Information Discovery is the Endeca Server, a hybrid search-analytical database that his highly scalable and column-oriented in nature. We will talk in more technical detail about the capabilities of the Endeca Server in future blog posts as this post is intended to give you a feel for the deep search capabilities that are an integral part of the Endeca Server. The Endeca Server provides best-of-breed search features aw well as a new class of features that are the first to be designed around the requirement to bridge structured, semi-structured and unstructured big data. Some of the key features of search include type a heads, automatic alphanumeric spell corrections, positional search, Booleans, wildcarding, natural language, and category search and query classification dialogs. This is just a subset of the advanced search capabilities found in Oracle Endeca Information Discovery. Search is an important feature that makes it possible for business users to explore on the diverse data sets the Endeca Server can hold at any one time. The search capabilities in the Endeca server differ from other Information Discovery products with simple “search boxes” in the following ways: The Endeca Server Supports Exploratory Search.  Enterprise data frequently requires the user to explore content through an ad hoc dialog, with guidance that helps them succeed. This has implications for how to design search features. Traditional search doesn’t assume a dialog, and so it uses relevance ranking to get its best guess to the top of the results list. It calculates many relevance factors for each query, like word frequency, distance, and meaning, and then reduces those many factors to a single score based on a proprietary “black box” formula. But how can a business users, searching, act on the information that the document is say only 38.1% relevant? In contrast, exploratory search gives users the opportunity to clarify what is relevant to them through refinements and summaries. This approach has received consumer endorsement through popular ecommerce sites where guided navigation across a broad range of products has helped consumers better discover choices that meet their, sometimes undetermined requirements. This same model exists in Oracle Endeca Information Discovery. In fact, the Endeca Server powers many of the most popular e-commerce sites in the world. The Endeca Server Supports Cascading Relevance. Traditional approaches of search reduce many relevance weights to a single score. This means that if a result with a good title match gets a similar score to one with an exact phrase match, they’ll appear next to each other in a list. But a user can’t deduce from their score why each got it’s ranking, even though that information could be valuable. Oracle Endeca Information Discovery takes a different approach. The Endeca Server stratifies results by a primary relevance strategy, and then breaks ties within a strata by ordering them with a secondary strategy, and so on. Application managers get the explicit means to compose these strategies based on their knowledge of their own domain. This approach gives both business users and managers a deterministic way to set and understand relevance. Now that you have an understanding of two of the core search capabilities in Oracle Endeca Information Discovery, our next blog post on this topic will discuss more advanced features including set search, second-order relevance as well as an understanding of faceted search mechanisms that include queries and filters.  

    Read the article

  • Find Knowledge Quickly

    - by Get Proactive Customer Adoption Team
    Untitled Document Get to relevant knowledge on the Oracle products you use in a few quick steps! Customers tell us that the volume of search results returned can make it difficult to find the information they need, especially when similar Oracle products exist. These simple tips show you how to filter, browse, search, and refine your results to get relevant answers faster. Filter first: PowerView is your best friend Powerview is an often ignored feature of My Oracle Support that enables you to control the information displayed on the Dashboard, the Knowledge tab and regions, and the Service Request tab based on one or more parameters. You can define a PowerView to limit information based on product, product line, support ID, platform, hostname, system name and others. Using PowerView allows you to restrict: Your search results to the filters you have set The product list when selecting your products in Search & Browse and when creating service requests   The PowerView menu is at the top of My Oracle Support, near the title You turn PowerView on by clicking PowerView is Off, which is a button. When PowerView is On, and filters are active, clicking the button again will toggle Powerview off. Click the arrow to the right to create new filters, edit filters, remove a filter, or choose from the list of previously created filters. You can create a PowerView in 3 simple steps! Turn PowerView on and select New from the PowerView menu. Select your filter from the Select Filter Type dropdown list and make selections from the other two menus. Hint: While there are many filter options, selecting your product line or your list of products will provide you with an effective filter. Click the plus sign (+) to add more filters. Click the minus sign (-) to remove a filter. Click Create to save and activated the filter(s) You’ll notice that PowerView is On displays along with the active filters. For more information about the PowerView capabilities, click the Learn more about PowerView… menu item or view a short video. Browse & Refine: Access the Best Match Fast For Your Product and Task In the Knowledge Browse region of the Knowledge or Dashboard tabs, pick your product, pick your task, select a version, if applicable. A best match document – a collection of knowledge articles and resources specific to your selections - may display, offering you a one-stop shop. The best match document, called an “information center,” is an aggregate of dynamically updated links to information pertinent to the product, task, and version (if applicable) you chose. These documents are refreshed every 24 hours to ensure that you have the most current information at your fingertips. Note: Not all products have “information centers.” If no information center appears as a best match, click Search to see a list of search results. From the information center, you can access topics from a product overview to security information, as shown in the left menu. Just want to search? That’s easy too! Again, pick your product, pick your task, select a version, if applicable, enter a keyword term, and click Search. Hint: In this example, you’ll notice that PowerView is on and set to PeopleSoft Enterprise. When PowerView is on and you select a product from the Knowledge Base product list, the listed products are limited to the active PowerView filter. (Products you’ve previously picked are also listed at the top of the dropdown list.) Your search results are displayed based on the parameters you entered. It’s that simple! Related Information: My Oracle Support - User Resource Center [ID 873313.1] My Oracle Support Community For more tips on using My Oracle Support, check out these short video training modules. My Oracle Support Speed Video Training [ID 603505.1]

    Read the article

  • Strategies for invoking subclass methods on generic objects

    - by Brad Patton
    I've run into this issue in a number of places and have solved it a bunch of different ways but looking for other solutions or opinions on how to address. The scenario is when you have a collection of objects all based off of the same superclass but you want to perform certain actions based only on instances of some of the subclasses. One contrived example of this might be an HTML document made up of elements. You could have a superclass named HTMLELement and subclasses of Headings, Paragraphs, Images, Comments, etc. To invoke a common action across all of the objects you declare a virtual method in the superclass and specific implementations in all of the subclasses. So to render the document you could loop all of the different objects in the document and call a common Render() method on each instance. It's the case where again using the same generic objects in the collection I want to perform different actions for instances of specific subclass (or set of subclasses). For example (an remember this is just an example) when iterating over the collection, elements with external links need to be downloaded (e.g. JS, CSS, images) and some might require additional parsing (JS, CSS). What's the best way to handle those special cases. Some of the strategies I've used or seen used include: Virtual methods in the base class. So in the base class you have a virtual LoadExternalContent() method that does nothing and then override it in the specific subclasses that need to implement it. The benefit being that in the calling code there is no object testing you send the same message to each object and let most of them ignore it. Two downsides that I can think of. First it can make the base class very cluttered with methods that have nothing to do with most of the hierarchy. Second it assumes all of the work can be done in the called method and doesn't handle the case where there might be additional context specific actions in the calling code (i.e. you want to do something in the UI and not the model). Have methods on the class to uniquely identify the objects. This could include methods like ClassName() which return a string with the class name or other return values like enums or booleans (IsImage()). The benefit is that the calling code can use if or switch statements to filter objects to perform class specific actions. The downside is that for every new class you need to implement these methods and can look cluttered. Also performance could be less than some of the other options. Use language features to identify objects. This includes reflection and language operators to identify the objects. For example in C# there is the is operator that returns true if the instance matches the specified class. The benefit is no additional code to implement in your object hierarchy. The only downside seems to be the lack of using something like a switch statement and the fact that your calling code is a little more cluttered. Are there other strategies I am missing? Thoughts on best approaches?

    Read the article

  • News From EAP Testing

    - by Fatherjack
    There is a phrase that goes something like “Watch the pennies and the pounds/dollars will take care of themselves”, meaning that if you pay attention to the small things then the larger things are going to fare well too. I am lucky enough to be a Friend of Red Gate and once in a while I get told about new features in their tools and have a test copy of the software to trial. I got one of those emails a week or so ago and I have been exploring the SQL Prompt 6 EAP since then. One really useful feature of long standing in SQL Prompt is the idea of a code snippet that is automatically pasted into the SSMS editor when you type a few key letters. For example I can type “ssf” and then press the tab key and the text is expanded to SELECT * FROM. There are lots of these combinations and it is possible to create your own really easily. To create your own you use the Snippet Manager interface to define the shortcut letters and the code that you want to have put in their place. Let’s look at an example. Say I am writing a blog about something and want to have the demo code create a temporary table. It might looks like this; The first time you run the code everything is fine, a lovely set of dates fill the results grid but run it a second time and this happens.   Yep, we didn’t destroy the temporary table so the CREATE statement fails when it finds the table already exists. No matter, I have a snippet created that takes care of this.   Nothing too technical here but you will see that in the Code section there is $CURSOR$, this isn’t a TSQL keyword but a marker for SQL Prompt to place the cursor in that position when the Code is pasted into the SSMS Editor. I just place my cursor above the CREATE statement and type “ifobj” – the shortcut for my code to DROP the temporary table – which has been defined in the Snippet Manager as below. This means I am right-away ready to type the name of the offending table. Pretty neat and it’s been very useful in saving me lots of time over many years.   The news for SQL Prompt 6 is that Red Gate have added a new Snippet Command of $PASTE$. Let’s alter our snippet to the following and try it out   Once again, we will type type “ifobj” in the SSMS Editor but first of all, highlight the name of the table #TestTable and copy it to your clipboard. Now type “ifobj” and press Tab… Wherever the string $PASTE$ is placed in the snippet, the contents of your clipboard are merged into the pasted TSQL. This means I don’t need to type the table name into the code snippet, it’s already there and I am seeing a fully functioning piece of TSQL ready to run. This means it is it even easier to write TSQL quickly and consistently. Attention to detail like this from Red Gate means that their developer tools stay on track to keep winning awards year after year and help take the hard work out of writing neat, accurate TSQL. If you want to try out SQL Prompt all the details are at http://www.red-gate.com/products/sql-development/sql-prompt/.

    Read the article

  • My shiny new gadget

    - by TechTwaddle
    About 3 months ago when I had tweeted (or twit?) that the HD7 could be my next phone I wasn’t a 100 percent sure, and when the HTC Mozart came out it was switch at first sight. I wanted to buy the Mozart mainly for three reasons; its unibody construction, smaller screen and the SLCD display. But now, holding a HD7 in my hand, I reminisce and think about how fate had its own plan. Too dramatic for a piece of gadget? Well, sort of, but seriously, this has been most exciting. So in short, I bought myself a HTC HD7 and am really loving it so far. Here are some pics (taken from my HD2 which now lies in a corner, crying),     Most of my day was spent setting up the device. Email accounts, Facebook, Marketplace etc. Since marketplace isn’t officially launched in India yet, my primary live id did not work. Whenever I tried launching marketplace it would say ‘marketplace is not currently supported in your country’. Searching the forums I found an easy work around. Just create a dummy live id with the country set to UK or US and log in to the device using this id. I was worried if the contacts and feeds from my primary live account would not be updated but that was not a problem. Adding another live account into the device does import your contacts, calendar and feeds from it. And that’s it, marketplace now works perfectly. I installed a few trial and free applications; haven’t checked if I can purchase apps though, will check that later and update this post. There is one issue I am still facing with the device, I can’t access the internet over GPRS. Windows Phone 7 only gives you the option to add an ‘APN’ and nothing else. Checking the connection settings on my HD2, I found out that there is also a proxy server I need to add to access GPRS, but so far I haven’t found a way to do that on WP7. Ideally HTC should have taken care of this, detect the operator and apply that operators settings on the device, but looks like that’s not happening. I also tried the ‘Connection Settings’ application that HTC bundled with the device, but it did nothing magical. If you’re reading this and know how to fix this problem please leave a comment. The next thing I did is install apps, a lot of apps. Read Engadget’s guide to essential apps for WP7. The apps and games I installed so far include Beezz (twitter app with push notifications), twitter (the official twitter app), Facebook, Youtube, NFS Undercover, Rocket Riot, Krashlander, Unite and the list goes on. All the apps run super smooth. The display looks fine indoors but I know it’s going to suck in bright sunlight. Anyhow, I am really impressed with what I’ve seen so far. I leave you with a few more photos. Have a great year ahead. Ciao!

    Read the article

  • Why googling by keycaptcha gives results on reCAPTCHA? [closed]

    - by vgv8
    EDIT: I'd like to change this title to: How to STOP Google's manipulation of Google search engine presented to general public? I am frequently googling and more and more frequently bump when searching by one software product I am given instead the results on Google's own products. For ex., if I google by keyword keycaptcha for the "Past 24 hours" (after clicking on "Show search tools" -- "Past 24 hours" on the left sidebar of a browser) I am getting the Google's search results show only results on reCAPTCHA. Image uploaded later: Though, if confine keycaptcha in quotes the results are "correct" (well, kind of since they are still distorted in comparison with other search engines). I checked this during few months from different domains at different ISPs, different operating systems and from a dozen of browsers. The results are the same. Why is it and how can it be possibly corrected? My related posts: "How Gmail spam filter works?" IP adresses blacklisting Update: It is impossible for me to directly start using google.com as I am always redirected to google.ru (from google.com) by my ip-address "auto-detect location" google's "convenience". The google's help tells that it is impossible to switch off my location auto-detection because it is very helpful feature. There is a work-around to use google.com/ncr (to get google.com) (?anybody know what does it mean) to prevent redirection from google.com but even. But all results are exactly the same OK, I can search by quoted "keycaptcha", I am already accustomed to these google's quirks, but the question arises why the heck to burn time promoting someone's product if GOOGLE uses other product brands for showing its own interests/brands (reCAPTCHA) instead and what can be done with it? The general user will not understand that he was cheated and just will pick up the first (wrong) results Update2: Note that this googling behaviour: is independent on whether I am logged-in (or log-out-ed of) a google account, which account, on browser (I tried Opera, Chrome, FireFox, IE of different versions, Safari), OS or even domain; there are many such cases but I just targeted one concrete restricted example speciffically to to prevent wandering between unrelated details and peculiarities; @Michael, first it is not true and this text contains 2 links for real and significant results.. I also wrote that this is just one concrete example from many and based on many-month exp. These distortions happen upon clicking on: Past 24 hours, Past week, Past month, Past year in many other keywords, occasions/configurations of searches, etc. Second, the absence of the results is the result and there is no point to sneakingly substitute it by another unsolicited one. It is the definition of spam and scam. 3d, the question is not abt workarounds like how to write search queries or use another searching engines. The question is how to straighten the googling's results in order to stop disorienting general public about. Update: I could not understand: nobody reproduces the described by me behavior (i.e. when I click "Past 24 hours" link in google search searching for keycaptcha, the presented results are only on reCAPTCHA presented)? Update: And for the "Past week":

    Read the article

  • New Version 3.1 Endeca Information Discovery Now Available

    - by Mike.Hallett(at)Oracle-BI&EPM
    Normal 0 false false false EN-GB X-NONE X-NONE MicrosoftInternetExplorer4 Business User Self-Service Data Mash-up Analysis and Discovery integrated with OBI11g and Hadoop Oracle Endeca Information Discovery 3.1 (OEID) is a major release that incorporates significant new self-service discovery capabilities for business users, including agile data mashup, extended support for unstructured analytics, and an even tighter integration with Oracle BI.  · Self-Service Data Mashup and Discovery Dashboards: business users can combine information from multiple sources, including their own up-loaded spreadsheets, to conduct analysis on the complete set.  Creating discovery dashboards has been made even easier by intuitive drag-and drop layouts and wizard-based configuration.  Business users can now build new discovery applications in minutes, without depending on IT. · Enhanced Integration with Oracle BI: OEID 3.1 enhances its’ native integration with Oracle Business Intelligence Foundation. Business users can now incorporate information from trusted BI warehouses, leveraging dimensions and attributes defined in Oracle’s Common Enterprise Information Model, but evolve them based on the varying day-to-day demands and requirements that they personally manage. · Deep Unstructured Analysis: business users can gain new insights from a wide variety of enterprise and public sources, helping companies to build an actionable Big Data strategy.  With OEID’s long-standing differentiation in correlating unstructured information with structured data, business users can now perform their own text mining to identify hidden concepts, without having to request support from IT. They can augment these insights with best in class keyword search and pattern matching, all in the context of rich, interactive visualizations and analytic summaries. · Enterprise-Class Self-Service Discovery:  OEID 3.1 enables IT to provide a powerful self-service platform to the business as part of a broader Business Analytics strategy, preserving the value of existing investments in data quality, governance, and security.  Business users can take advantage of IT-curated information to drive discovery across high volumes and varieties of data, and share insights with colleagues at a moment’s notice. · Harvest Content from the Web with the Endeca Web Acquisition Toolkit:  Oracle now provides best-of-breed data access to website content through the Oracle Endeca Web Acquisition Toolkit.  This provides an agile, graphical interface for developers to rapidly access and integrate any information exposed through a web front-end.  Organizations can now cost-effectively include content from consumer sites, industry forums, government or supplier portals, cloud applications, and myriad other web sources as part of their overall strategy for data discovery and unstructured analytics. For more information: OEID 3.1 OTN Software and Documentation Download And Endeca available for download on Software Delivery Cloud (eDelivery) New OEID 3.1 Videos on YouTube Oracle.com Endeca Site /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;}

    Read the article

  • Questions to ask to ensure someone understands programming? (and iOS)

    - by Stephen J
    So, I've been tutoring my friend for 2 years. Most people learn programming on their own in 3-6 months, (sans algorithms). It's confusing 'cause he'll run anywhere I tell him to, understands how to read C and C++ honestly better than the average college student, and he'll modify and repeat anything I do... but for the love of god he doesn't move on to new things and he still has test anxiety. I've recently realized he's copied and toyed with existing, but not once gained an understanding of why. I was under the impression he was learning fast because he could write it, but when you say "Make a function that takes an NSString" and he says "How?" and I say "The same way you make ANY function that takes any parameter, NSString is just a type like int" and all I hear is "No, it's an NSString, it's a special thing." and we get into an arguing match 'cause I'm like "It's just a class like any other class, you've used them for months now" and blah... I've subconsciously avoided comprehension questions because of this. Anyway, if you have him copy a program and say "Just initialize it" "Where?" "I don't care, didLoad or initWithCoder or Awake from nib, anywhere it gets initialized" and "No, it has to be exactly where you had it!" "No it doesn't!" I'm sick of this, but he won't give up. So I'm done avoiding these yelling matches and becoming a sadist from now on. I would like some help in finding questions to ask him that force him to understand what he's doing. I'd like some help and any resources I can find. CQuestions looked like a good site, but now I need some iPhone stuff. For example: *What do properties do? How are they changed? How do you change the name of the getter? *Why are Booleans inefficent? What advantage does int have over a boolean and how does the bit-shift operator help? *What does Copy do to a string? *What's the difference between a view controller and a uiview? *Write a program from memory that displays blah on screen, and flashes each view one by one. From beginner up to intermediate, hobbyist with some algebra at most. I'm just looking for resources to work with. I left in backstory so you know to "twist" the questions so he doesn't know he's supposed to init a variable here or there, but has to figure it out, and learn why it goes "here" or that "anywhere is fine as long as it's". Sample programs, anything. I'm relatively open about this because, being a programmer, I seriously doubt he's the only one who has this issue. I'd like to know how others have overcome similar. What made things "click"? for you? Did you have a hard time finding answers on Google, and how did you learn a better way to find what you were looking for? (He's so exact, he'll search for how to write a checkers program with color X and Y inside a uiview, as his search string, instead of breaking it up into components, I need help with that too, and believe it is related). This type of problem has to remind one of us of someone they know. So, Exercises to force them to think? Ways we overcame this thing in the past? I greatly appreciate any help.

    Read the article

  • Consumer Oriented Search In Oracle Endeca Information Discovery - Part 2

    - by Bob Zurek
    As discussed in my last blog posting on this topic, Information Discovery, a core capability of the Oracle Endeca Information Discovery solution enables businesses to search, discover and navigate through a wide variety of big data including structured, unstructured and semi-structured data. With search as a core advanced capabilities of our product it is important to understand some of the key differences and capabilities in the underlying data store of Oracle Endeca Information Discovery and that is our Endeca Server. In the last post on this subject, we talked about Exploratory Search capabilities along with support for cascading relevance. Additional search capabilities in the Endeca Server, which differentiate from simple keyword based "search boxes" in other Information Discovery products also include: The Endeca Server Supports Set Search.  The Endeca Server is organized around set retrieval, which means that it looks at groups of results (all the documents that match a search), as well as the relationship of each individual result to the set. Other approaches only compute the relevance of a document by comparing the document to the search query – not by comparing the document to all the others. For example, a search for “U.S.” in another approach might match to the title of a document and get a high ranking. But what if it were a collection of government documents in which “U.S.” appeared in many titles, making that clue less meaningful? A set analysis would reveal this and be used to adjust relevance accordingly. The Endeca Server Supports Second-Order Relvance. Unlike simple search interfaces in traditional BI tools, which provide limited relevance ranking, such as a list of results based on key word matching, Endeca enables users to determine the most salient terms to divide up the result. Determining this second-order relevance is the key to providing effective guidance. Support for Queries and Filters. Search is the most common query type, but hardly complete, and users need to express a wide range of queries. Oracle Endeca Information Discovery also includes navigation, interactive visualizations, analytics, range filters, geospatial filters, and other query types that are more commonly associated with BI tools. Unlike other approaches, these queries operate across structured, semi-structured and unstructured content stored in the Endeca Server. Furthermore, this set is easily extensible because the core engine allows for pluggable features to be added. Like a search engine, queries are answered with a results list, ranked to put the most likely matches first. Unlike “black box” relevance solutions, which generalize one strategy for everyone, we believe that optimal relevance strategies vary across domains. Therefore, it provides line-of-business owners with a set of relevance modules that let them tune the best results based on their content. The Endeca Server query result sets are summarized, which gives users guidance on how to refine and explore further. Summaries include Guided Navigation® (a form of faceted search), maps, charts, graphs, tag clouds, concept clusters, and clarification dialogs. Users don’t explicitly ask for these summaries; Oracle Endeca Information Discovery analytic applications provide the right ones, based on configurable controls and rules. For example, the analytic application might guide a procurement agent filtering for in-stock parts by visualizing the results on a map and calculating their average fulfillment time. Furthermore, the user can interact with summaries and filters without resorting to writing complex SQL queries. The user can simply just click to add filters. Within Oracle Endeca Information Discovery, all parts of the summaries are clickable and searchable. We are living in a search driven society where business users really seem to enjoy entering information into a search box. We do this everyday as consumers and therefore, we have gotten used to looking for that box. However, the key to getting the right results is to guide that user in a way that provides additional Discovery, beyond what they may have anticipated. This is why these important and advanced features of search inside the Endeca Server have been so important. They have helped to guide our great customers to success. 

    Read the article

  • What Counts For a DBA – Depth

    - by Louis Davidson
    SQL Server offers very simple interfaces to many of its features. Most people could open up SSMS, connect to a server, write a simple query and see the results. Even several of the core DBA tasks are deceptively straightforward. It doesn’t take a rocket scientist to perform a basic database backup or run a trace (even using the newfangled Extended Events!). However, appearances can be deceptive, and often times it is really important that a DBA understands not just the basics of how to perform a task, but why we do a task, and how that task works. As an analogy, consider a child walking into a darkened room. Most would know that they need to turn on the light, and how to do it, so they flick the switch. But what happens if light fails to shine forth. Most would immediately tell you that you need to consider changing the light bulb. So you hop in the car and take them to the local home store and instruct them to buy a replacement. Confronted with a 40 foot display of light bulbs, how will they decide which of the hundreds of types of bulbs, of different types, fittings, shapes, colors, power and efficiency ratings, is the right choice? Obviously the main lesson the child is going to learn this day is how to use their cell phone as a flashlight so they don’t have to ask for help the next time. Likewise, when the metaphorical toddlers who use your database server have issues, they will instinctively know something is wrong, and may even have some idea what caused it, but will have no depth of knowledge to figure out the right solution. That is where the DBA comes in and attempts to save the day. However, when one looks beneath the shiny UI, SQL Server has its own “40 foot display of light bulbs”, in the form of the tremendous number of tools and the often-bewildering amount of information they can present to the DBA, to help us find issues. Unfortunately, resorting to guesswork, to trying different “bulbs” over and over, hoping to stumble on the answer. This is where the right depth of knowledge goes a long way. If we need to write a SELECT statement, then knowing the syntax and where to find the data is not enough. Knowledge of indexes and query plans is essential. Without it, we might hit on a query that “works”, but we are basically still a user, not a programmer, because we have no real control over our platform. Is that level of knowledge deep enough? Probably not, since knowledge of the underlying metadata and structures would be very useful in helping us make sense of any query plan. Understanding the structure of an index makes the “key lookup” operator not sound like what you do when someone tapes your car key to the ceiling. So is even this level of understanding deep enough? Do we need to understand the memory architecture used to process the query? It might be a comforting level of knowledge, and will doubtless come in handy at some point, but is not strictly necessary in most cases. Beyond that lies (more or less) full knowledge of SQL language and the intricacies of every step the SQL Server engine takes to process our query. My personal theory is that, as a professional, our knowledge of a given task should extend, at a minimum, one level deeper than is strictly necessary to perform the task. Anything deeper can be left to the ridiculously smart, or obsessive, or both. As an example. tasked with storing an integer value between 0 and 99999999, it’s essential that I know that choosing an Integer over Decimal(8,0) will likely offer performance benefits. It is then useful that I also understand the value of adding a CHECK constraint, to make sure the values are valid to the desired range; and comforting that I know a little about the underlying processors, registers and computer math. Anything further, I leave to the likes of Joe Chang, whose recent blog post on the topic offers depth by the bucketful!  

    Read the article

  • C# Dev Challenge Part 1 of n &ndash; Beginner Edition

    - by mbcrump
    I developed this challenge to test one’s knowledge of C Sharp. I am planning on creating several challenges with different skill sets, so don’t get mad if this challenge doesn’t well challenge you... I noticed that most people like short quizzes so this one only contains 5 questions. All of the challenges are clear and concise of what I am asking you to do. No smoke and mirrors here, meaning that none of the code has syntax errors. The purpose of this exercise is to test several OOP concepts and see how much of the C# language you really know. Question #1 – Lets start off Easy… Will the following code snippet compile successfully? What does this question test? - Can this compile without a namespace? Do you have to have an entry point of “static void Main()”? class Test { static int Main() { System.Console.WriteLine("Developer Challenge"); return 0; } } Answer (select text in box below): Yes, it will compile successfully. Question #2 – What is the value of the Console.WriteLine statements? What does this question test? – Do I understand reference types/value types? If a variable is declared with the @ symbol and its not a reserved keyword does the application compile successfully? using System; internal struct MyStruct { public int Value; } internal class MyClass { public int Value; } class Test { static void Main() { MyStruct @struct1 = new MyStruct(); MyStruct @struct2 = @struct1; @struct2.Value = 100; MyClass @ref1 = new MyClass(); MyClass @ref2 = @ref1; @ref2.Value = 100; Console.WriteLine("Value Type: {0} {1}", @struct1.Value, @struct2.Value); Console.WriteLine("Reference Type: {0} {1}", @ref1.Value, @ref2.Value); } } Answer (select text in box below): Value Type: 0 100 Reference Type: 100 100 Question #3 – What is the value of the Console.WriteLine statements? What does this question test? – Can 2 objects reference the same point in memory? using System; class Test { static void Main() { string s1 = "Testing2"; string t1 = s1; Console.WriteLine(s1 == t1); Console.WriteLine((object)s1 == (object)t1); } } Answer (select text in box below): True True Question #4 – What is the value of the Console.WriteLine statements? What does this question test? – How does the “Stack” work – LIFO or FIFO?   using System; using System.Collections; class Test { static void Main() { Stack a = new Stack(5); a.Push("1"); a.Push("2"); a.Push("3"); a.Push("4"); a.Push("5"); foreach (var o in a) { Console.WriteLine(o); } } } Answer (select text in box below): 5 4 3 2 1 Question #5 – What is the value of the Console.WriteLine statements? What does this question test? – Array and General Looping Knowledge. using System; namespace ConsoleApplication5 { class Program { static void Main(string[] args) { int[] J_LIST = new int[5] { 1, 2, 3, 4, 5 }; int K = 10; int L = 5; foreach (var J in J_LIST) { K = K - J; L = K + 2 * J; Console.WriteLine("J = {0, 5} K = {1, 5} L = {2, 5}", J, K, L); } Console.ReadLine(); } } } Answer (select text in box below): J = 1 K = 9 L = 11 J = 2 K = 7 L = 11 J = 3 K = 4 L = 10 J = 4 K = 0 L = 8 J = 5 K = -5 L = 5 Stay Tuned for more challenges!

    Read the article

  • Mulitple full joins in Postgres is slow

    - by blast83
    I have a program to use the IMDB database and am having very slow performance on my query. It appears that it doesn't use my where condition until after it materializes everything. I looked around for hints to use but nothing seems to work. Here is my query: SELECT * FROM name as n1 FULL JOIN aka_name ON n1.id = aka_name.person_id FULL JOIN cast_info as t2 ON n1.id = t2.person_id FULL JOIN person_info as t3 ON n1.id = t3.person_id FULL JOIN char_name as t4 ON t2.person_role_id = t4.id FULL JOIN role_type as t5 ON t2.role_id = t5.id FULL JOIN title as t6 ON t2.movie_id = t6.id FULL JOIN aka_title as t7 ON t6.id = t7.movie_id FULL JOIN complete_cast as t8 ON t6.id = t8.movie_id FULL JOIN kind_type as t9 ON t6.kind_id = t9.id FULL JOIN movie_companies as t10 ON t6.id = t10.movie_id FULL JOIN movie_info as t11 ON t6.id = t11.movie_id FULL JOIN movie_info_idx as t19 ON t6.id = t19.movie_id FULL JOIN movie_keyword as t12 ON t6.id = t12.movie_id FULL JOIN movie_link as t13 ON t6.id = t13.linked_movie_id FULL JOIN link_type as t14 ON t13.link_type_id = t14.id FULL JOIN keyword as t15 ON t12.keyword_id = t15.id FULL JOIN company_name as t16 ON t10.company_id = t16.id FULL JOIN company_type as t17 ON t10.company_type_id = t17.id FULL JOIN comp_cast_type as t18 ON t8.status_id = t18.id WHERE n1.id = 2003 Very table is related to each other on the join via foreign-key constraints and have indexes for all the mentioned columns. The query plan details: "Hash Left Join (cost=5838187.01..13756845.07 rows=15579622 width=835) (actual time=146879.213..146891.861 rows=20 loops=1)" " Hash Cond: (t8.status_id = t18.id)" " -> Hash Left Join (cost=5838185.92..13542624.18 rows=15579622 width=822) (actual time=146879.199..146891.833 rows=20 loops=1)" " Hash Cond: (t10.company_type_id = t17.id)" " -> Hash Left Join (cost=5838184.83..13328403.29 rows=15579622 width=797) (actual time=146879.165..146891.781 rows=20 loops=1)" " Hash Cond: (t10.company_id = t16.id)" " -> Hash Left Join (cost=5828372.95..10061752.03 rows=15579622 width=755) (actual time=146426.483..146429.756 rows=20 loops=1)" " Hash Cond: (t12.keyword_id = t15.id)" " -> Hash Left Join (cost=5825164.23..6914088.45 rows=15579622 width=731) (actual time=146372.411..146372.529 rows=20 loops=1)" " Hash Cond: (t13.link_type_id = t14.id)" " -> Merge Left Join (cost=5825162.82..6699867.24 rows=15579622 width=715) (actual time=146372.366..146372.472 rows=20 loops=1)" " Merge Cond: (t6.id = t13.linked_movie_id)" " -> Merge Left Join (cost=5684009.29..6378956.77 rows=15579622 width=699) (actual time=144019.620..144019.711 rows=20 loops=1)" " Merge Cond: (t6.id = t12.movie_id)" " -> Merge Left Join (cost=5182403.90..5622400.75 rows=8502523 width=687) (actual time=136849.731..136849.809 rows=20 loops=1)" " Merge Cond: (t6.id = t19.movie_id)" " -> Merge Left Join (cost=4974472.00..5315778.48 rows=8502523 width=637) (actual time=134972.032..134972.099 rows=20 loops=1)" " Merge Cond: (t6.id = t11.movie_id)" " -> Merge Left Join (cost=1830064.81..2033131.89 rows=1341632 width=561) (actual time=63784.035..63784.062 rows=2 loops=1)" " Merge Cond: (t6.id = t10.movie_id)" " -> Nested Loop Left Join (cost=1417360.29..1594294.02 rows=1044480 width=521) (actual time=59279.246..59279.264 rows=1 loops=1)" " Join Filter: (t6.kind_id = t9.id)" " -> Merge Left Join (cost=1417359.22..1429787.34 rows=1044480 width=507) (actual time=59279.222..59279.224 rows=1 loops=1)" " Merge Cond: (t6.id = t8.movie_id)" " -> Merge Left Join (cost=1405731.84..1414378.65 rows=1044480 width=491) (actual time=59121.773..59121.775 rows=1 loops=1)" " Merge Cond: (t6.id = t7.movie_id)" " -> Sort (cost=1346206.04..1348817.24 rows=1044480 width=416) (actual time=58095.230..58095.231 rows=1 loops=1)" " Sort Key: t6.id" " Sort Method: quicksort Memory: 17kB" " -> Hash Left Join (cost=172406.29..456387.53 rows=1044480 width=416) (actual time=57969.371..58095.208 rows=1 loops=1)" " Hash Cond: (t2.movie_id = t6.id)" " -> Hash Left Join (cost=104700.38..256885.82 rows=1044480 width=358) (actual time=49981.493..50006.303 rows=1 loops=1)" " Hash Cond: (t2.role_id = t5.id)" " -> Hash Left Join (cost=104699.11..242522.95 rows=1044480 width=343) (actual time=49981.441..50006.250 rows=1 loops=1)" " Hash Cond: (t2.person_role_id = t4.id)" " -> Hash Left Join (cost=464.96..12283.95 rows=1044480 width=269) (actual time=0.071..0.087 rows=1 loops=1)" " Hash Cond: (n1.id = t3.person_id)" " -> Nested Loop Left Join (cost=0.00..49.39 rows=7680 width=160) (actual time=0.051..0.066 rows=1 loops=1)" " -> Nested Loop Left Join (cost=0.00..17.04 rows=3 width=119) (actual time=0.038..0.041 rows=1 loops=1)" " -> Index Scan using name_pkey on name n1 (cost=0.00..8.68 rows=1 width=39) (actual time=0.022..0.024 rows=1 loops=1)" " Index Cond: (id = 2003)" " -> Index Scan using aka_name_idx_person on aka_name (cost=0.00..8.34 rows=1 width=80) (actual time=0.010..0.010 rows=0 loops=1)" " Index Cond: ((aka_name.person_id = 2003) AND (n1.id = aka_name.person_id))" " -> Index Scan using cast_info_idx_pid on cast_info t2 (cost=0.00..10.77 rows=1 width=41) (actual time=0.011..0.020 rows=1 loops=1)" " Index Cond: ((t2.person_id = 2003) AND (n1.id = t2.person_id))" " -> Hash (cost=463.26..463.26 rows=136 width=109) (actual time=0.010..0.010 rows=0 loops=1)" " -> Index Scan using person_info_idx_pid on person_info t3 (cost=0.00..463.26 rows=136 width=109) (actual time=0.009..0.009 rows=0 loops=1)" " Index Cond: (person_id = 2003)" " -> Hash (cost=42697.62..42697.62 rows=2442362 width=74) (actual time=49305.872..49305.872 rows=2442362 loops=1)" " -> Seq Scan on char_name t4 (cost=0.00..42697.62 rows=2442362 width=74) (actual time=14.066..22775.087 rows=2442362 loops=1)" " -> Hash (cost=1.12..1.12 rows=12 width=15) (actual time=0.024..0.024 rows=12 loops=1)" " -> Seq Scan on role_type t5 (cost=0.00..1.12 rows=12 width=15) (actual time=0.012..0.014 rows=12 loops=1)" " -> Hash (cost=31134.07..31134.07 rows=1573507 width=58) (actual time=7841.225..7841.225 rows=1573507 loops=1)" " -> Seq Scan on title t6 (cost=0.00..31134.07 rows=1573507 width=58) (actual time=21.507..2799.443 rows=1573507 loops=1)" " -> Materialize (cost=59525.80..63203.88 rows=294246 width=75) (actual time=812.376..984.958 rows=192075 loops=1)" " -> Sort (cost=59525.80..60261.42 rows=294246 width=75) (actual time=812.363..922.452 rows=192075 loops=1)" " Sort Key: t7.movie_id" " Sort Method: external merge Disk: 24880kB" " -> Seq Scan on aka_title t7 (cost=0.00..6646.46 rows=294246 width=75) (actual time=24.652..164.822 rows=294246 loops=1)" " -> Materialize (cost=11627.38..12884.43 rows=100564 width=16) (actual time=123.819..149.086 rows=41907 loops=1)" " -> Sort (cost=11627.38..11878.79 rows=100564 width=16) (actual time=123.807..138.530 rows=41907 loops=1)" " Sort Key: t8.movie_id" " Sort Method: external merge Disk: 3136kB" " -> Seq Scan on complete_cast t8 (cost=0.00..1549.64 rows=100564 width=16) (actual time=0.013..10.744 rows=100564 loops=1)" " -> Materialize (cost=1.08..1.15 rows=7 width=14) (actual time=0.016..0.029 rows=7 loops=1)" " -> Seq Scan on kind_type t9 (cost=0.00..1.07 rows=7 width=14) (actual time=0.011..0.013 rows=7 loops=1)" " -> Materialize (cost=412704.52..437969.09 rows=2021166 width=40) (actual time=3420.356..4278.545 rows=1028995 loops=1)" " -> Sort (cost=412704.52..417757.43 rows=2021166 width=40) (actual time=3420.349..3953.483 rows=1028995 loops=1)" " Sort Key: t10.movie_id" " Sort Method: external merge Disk: 90960kB" " -> Seq Scan on movie_companies t10 (cost=0.00..35214.66 rows=2021166 width=40) (actual time=13.271..566.893 rows=2021166 loops=1)" " -> Materialize (cost=3144407.19..3269057.42 rows=9972019 width=76) (actual time=65485.672..70083.219 rows=5039009 loops=1)" " -> Sort (cost=3144407.19..3169337.23 rows=9972019 width=76) (actual time=65485.667..68385.550 rows=5038999 loops=1)" " Sort Key: t11.movie_id" " Sort Method: external merge Disk: 735512kB" " -> Seq Scan on movie_info t11 (cost=0.00..212815.19 rows=9972019 width=76) (actual time=15.750..15715.608 rows=9972019 loops=1)" " -> Materialize (cost=207925.01..219867.92 rows=955433 width=50) (actual time=1483.989..1785.636 rows=429401 loops=1)" " -> Sort (cost=207925.01..210313.59 rows=955433 width=50) (actual time=1483.983..1654.165 rows=429401 loops=1)" " Sort Key: t19.movie_id" " Sort Method: external merge Disk: 31720kB" " -> Seq Scan on movie_info_idx t19 (cost=0.00..15047.33 rows=955433 width=50) (actual time=7.284..221.597 rows=955433 loops=1)" " -> Materialize (cost=501605.39..537645.64 rows=2883220 width=12) (actual time=5823.040..6868.242 rows=1597396 loops=1)" " -> Sort (cost=501605.39..508813.44 rows=2883220 width=12) (actual time=5823.026..6477.517 rows=1597396 loops=1)" " Sort Key: t12.movie_id" " Sort Method: external merge Disk: 78888kB" " -> Seq Scan on movie_keyword t12 (cost=0.00..44417.20 rows=2883220 width=12) (actual time=11.672..839.498 rows=2883220 loops=1)" " -> Materialize (cost=141143.93..152995.81 rows=948150 width=16) (actual time=1916.356..2253.004 rows=478358 loops=1)" " -> Sort (cost=141143.93..143514.31 rows=948150 width=16) (actual time=1916.344..2125.698 rows=478358 loops=1)" " Sort Key: t13.linked_movie_id" " Sort Method: external merge Disk: 29632kB" " -> Seq Scan on movie_link t13 (cost=0.00..14607.50 rows=948150 width=16) (actual time=27.610..297.962 rows=948150 loops=1)" " -> Hash (cost=1.18..1.18 rows=18 width=16) (actual time=0.020..0.020 rows=18 loops=1)" " -> Seq Scan on link_type t14 (cost=0.00..1.18 rows=18 width=16) (actual time=0.010..0.012 rows=18 loops=1)" " -> Hash (cost=1537.10..1537.10 rows=91010 width=24) (actual time=54.055..54.055 rows=91010 loops=1)" " -> Seq Scan on keyword t15 (cost=0.00..1537.10 rows=91010 width=24) (actual time=0.006..14.703 rows=91010 loops=1)" " -> Hash (cost=4585.61..4585.61 rows=245461 width=42) (actual time=445.269..445.269 rows=245461 loops=1)" " -> Seq Scan on company_name t16 (cost=0.00..4585.61 rows=245461 width=42) (actual time=12.037..309.961 rows=245461 loops=1)" " -> Hash (cost=1.04..1.04 rows=4 width=25) (actual time=0.013..0.013 rows=4 loops=1)" " -> Seq Scan on company_type t17 (cost=0.00..1.04 rows=4 width=25) (actual time=0.009..0.010 rows=4 loops=1)" " -> Hash (cost=1.04..1.04 rows=4 width=13) (actual time=0.006..0.006 rows=4 loops=1)" " -> Seq Scan on comp_cast_type t18 (cost=0.00..1.04 rows=4 width=13) (actual time=0.002..0.003 rows=4 loops=1)" "Total runtime: 147055.016 ms" Is there anyway to force the name.id = 2003 before it tries to join all the tables together? As you can see, the end result is 4 tuples but it seems like it should be a fast join by using the available index after it limited it down with the name clause, although very complex.

    Read the article

  • C# Design How to Elegantly wrap a DAL class

    - by guazz
    I have an application which uses MyGeneration's dOODads ORM to generate it's Data Access Layer. dOODad works by generating a persistance class for each table in the database. It works like so: // Load and Save Employees emps = new Employees(); if(emps.LoadByPrimaryKey(42)) { emps.LastName = "Just Got Married"; emps.Save(); } // Add a new record Employees emps = new Employees(); emps.AddNew(); emps.FirstName = "Mr."; emps.LastName = "dOOdad"; emps.Save(); // After save the identity column is already here for me. int i = emps.EmployeeID; // Dynamic Query - All Employees with 'A' in thier last name Employees emps = new Employees(); emps.Where.LastName.Value = "%A%"; emps.Where.LastName.Operator = WhereParameter.Operand.Like; emps.Query.Load(); For the above example(i.e. Employees DAL object) I would like to know what is the best method/technique to abstract some of the implementation details on my classes. I don't believe that an Employee class should have Employees(the DAL) specifics in its methods - or perhaps this is acceptable? Is it possible to implement some form of repository pattern? Bear in mind that this is a high volume, perfomacne critical application. Thanks, j

    Read the article

  • Improving long-polling Ajax performance

    - by Bears will eat you
    I'm writing a webapp (Firefox-compatible only) which uses long polling (via jQuery's ajax abilities) to send more-or-less constant updates from the server to the client. I'm concerned about the effects of leaving this running for long periods of time, say, all day or overnight. The basic code skeleton is this: function processResults(xml) { // do stuff with the xml from the server } function fetch() { setTimeout(function () { $.ajax({ type: 'GET', url: 'foo/bar/baz', dataType: 'xml', success: function (xml) { processResults(xml); fetch(); }, error: function (xhr, type, exception) { if (xhr.status === 0) { console.log('XMLHttpRequest cancelled'); } else { console.debug(xhr); fetch(); } } }); }, 500); } (The half-second "sleep" is so that the client doesn't hammer the server if the updates are coming back to the client quickly - which they usually are.) After leaving this running overnight, it tends to make Firefox crawl. I'd been thinking that this could be partially caused by a large stack depth since I've basically written an infinitely recursive function. However, if I use Firebug and throw a breakpoint into fetch, it looks like this is not the case. The stack that Firebug shows me is only about 4 or 5 frames deep, even after an hour. One of the solutions I'm considering is changing my recursive function to an iterative one, but I can't figure out how I would insert the delay in between Ajax requests without spinning. I've looked at the JS 1.7 "yield" keyword but I can't quite wrap my head around it, to figure out if it's what I need here. Is the best solution just to do a hard refresh on the page periodically, say, once every hour? Is there a better/leaner long-polling design pattern that won't put a hurt on the browser even after running for 8 or 12 hours? Or should I just skip the long polling altogether and use a different "constant update" pattern since I usually know how frequently the server will have a response for me?

    Read the article

  • Populating Models from other Models in Django?

    - by JT
    This is somewhat related to the question posed in this question but I'm trying to do this with an abstract base class. For the purposes of this example lets use these models: class Comic(models.Model): name = models.CharField(max_length=20) desc = models.CharField(max_length=100) volume = models.IntegerField() ... <50 other things that make up a Comic> class Meta: abstract = True class InkedComic(Comic): lines = models.IntegerField() class ColoredComic(Comic): colored = models.BooleanField(default=False) In the view lets say we get a reference to an InkedComic id since the tracer, err I mean, inker is done drawing the lines and it's time to add color. Once the view has added all the color we want to save a ColoredComic to the db. Obviously we could do inked = InkedComic.object.get(pk=ink_id) colored = ColoredComic() colored.name = inked.name etc, etc. But really it'd be nice to do: colored = ColoredComic(inked_comic=inked) colored.colored = True colored.save() I tried to do class ColoredComic(Comic): colored = models.BooleanField(default=False) def __init__(self, inked_comic = False, *args, **kwargs): super(ColoredComic, self).__init__(*args, **kwargs) if inked_comic: self.__dict__.update(inked_comic.__dict__) self.__dict__.update({'id': None}) # Remove pk field value but it turns out the ColoredComic.objects.get(pk=1) call sticks the pk into the inked_comic keyword, which is obviously not intended. (and actually results in a int does not have a dict exception) My brain is fried at this point, am I missing something obvious, or is there a better way to do this?

    Read the article

  • Explicit casting doesn't work in default model binding

    - by Felix
    I am using ASP.NET MVC2 and Entity Framework. I am going to simplify the situation a little; hopefully it will make it clearer, not more confusing! I have a controller action to create address, and the country is a lookup table (in other words, there is a one-to-many relationship between Country and Address classes). Let's say for clarity that the field in the Address class is called Address.Land. And, for the purposes of the dropdown list, I am getting Country.CountryID and Country.Name. I am aware of Model vs. Input validation. So, if I call the dropdown field formLand - I can make it work. But if I call the field Land (that is, matching the variable in Address class) - I am getting the following error: "The parameter conversion from type 'System.String' to type 'App.Country' failed because no type converter can convert between these types." OK, this makes sense. A string (CountryID) comes from the form and the binder doesn't know how to convert it to Country type. So, I wrote the converter: namespace App { public partial class Country { public static explicit operator Country(string countryID) { AppEntities context = new AppEntities(); Country country = (Country) context.GetObjectByKey( new EntityKey("AppEntities.Countries", "CountryID", countryID)); return country; } } } FWIW, I tried both explicit and implicit. I tested it from the controller - Country c = (Country)"fr" - and it works fine. However, it never got invoked when the View is posted. I am getting the same "no type converter" error in the model. Any ideas how to hint to the model binder that there is a type converter? Thanks

    Read the article

< Previous Page | 146 147 148 149 150 151 152 153 154 155 156 157  | Next Page >