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• Agile Development Requires Agile Support

  - by Matt Watson

  Agile developmentAgile development has become the standard methodology for application development. The days of long term planning with giant Gantt waterfall charts and detailed requirements is fading away. For years the product planning process frustrated product owners and businesses because no matter the plan, nothing ever went to plan. Agile development throws the detailed planning out the window and instead focuses on giving developers some basic requirements and pointing them in the right direction. Constant collaboration via quick iterations with the end users, product owners, and the development team helps ensure the project is done correctly.  The various agile development methodologies have helped greatly with creating products faster, but not without causing new problems. Complicated application deployments now occur weekly or monthly. Most of the products are web-based and deployed as a software service model. System performance and availability of these apps becomes mission critical. This is all much different from the old process of mailing new releases of client-server apps on CD once per quarter or year.The steady stream of new products and product enhancements puts a lot of pressure on IT operations to keep up with the software deployments and adding infrastructure capacity. The problem is most operations teams still move slowly thanks to change orders, documentation, procedures, testing and other processes. Operations can slow the process down and push back on the development team in some organizations. The DevOps movement is trying to solve some of these problems by integrating the development and operations teams more together. Rapid change introduces new problemsThe rapid product change ultimately creates some application problems along the way. Higher rates of change increase the likelihood of new application defects. Delivering applications as a software service also means that scalability of applications is critical. Development teams struggle to keep up with application defects and scalability concerns in their applications. Fixing application problems is a never ending job for agile development teams. Fixing problems before your customers do and fixing them quickly is critical. Most companies really struggle with this due to the divide between the development and operations groups. Fixing application problems typically requires querying databases, looking at log files, reviewing config files, reviewing error logs and other similar tasks. It becomes difficult to work on new features when your lead developers are working on defects from the last product version. Developers need more visibilityThe problem is most developers are not given access to see server and application information in the production environments. The operations team doesn’t trust giving all the developers the keys to the kingdom to log in to production and poke around the servers. The challenge is either give them no access, or potentially too much access. Those with access can still waste time figuring out the location of the application and how to connect to it over VPN. In addition, reproducing problems in test environments takes too much time and isn't always possible. System administrators spend a lot of time helping developers track down server information. Most companies give key developers access to all of the production resources so they can help resolve application defects. The problem is only those key people have access and they become a bottleneck. They end up spending 25-50% of their time on a daily basis trying to solve application issues because they are the only ones with access. These key employees’ time is best spent on strategic new projects, not addressing application defects. This job should fall to entry level developers, provided they have access to all the information they need to troubleshoot the problems.The solution to agile application support is giving all the developers limited access to the production environment and all the server information they need to see. Some companies create their own solutions internally to collect log files, centralize errors or other things to address the problem. Some developers even have access to server monitoring or other tools. But they key is giving them access to everything they need so they can see the full picture and giving access to the whole team. Giving access to everyone scales up the application support team and creates collaboration around providing improved application support.Stackify enables agile application supportStackify has created a solution that can give all developers a secure and read only view of the entire production server environment without console or remote desktop access.They provide a web application that provides real time visibility to the important information that developers need to see. An application centric view enables them to see all of their apps across multiple datacenters and environments. They don’t need to know where the application is deployed, just the name of the application to find it and dig in to see more. All your developers can see server health, application health, log files, config files, windows event viewer, deployment history, application notes, and much more. They can receive email and text alerts when problems arise and even safely query your production databases.Stackify enables companies that do agile development to scale up their application support team by getting more team members involved. The lead developers can spend more time on new projects. Application issues can be fixed quicker than ever. Operations can spend less time helping developers collect server information. Agile application support starts with Stackify. Visit Stackify.com to learn more.

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• NDepend Evaluation: Part 3

  - by Anthony Trudeau

  NDepend is a Visual Studio add-in designed for intense code analysis with the goal of high code quality. NDepend uses a number of metrics and aggregates the data in pleasing static and active visual reports. My evaluation of NDepend will be broken up into several different parts. In the first part of the evaluation I looked at installing the add-in.  And in the last part I went over my first impressions including an overview of the features.  In this installment I provide a little more detail on a few of the features that I really like. Dependency Matrix The dependency matrix is one of the rich visual components provided with NDepend.  At a glance it lets you know where you have coupling problems including cycles.  It does this with number indicating the weight of the dependency and a color-coding that indicates the nature of the dependency. Green and blue cells are direct dependencies (with the difference being whether the relationship is from row-to-column or column-to-row).  Black cells are the ones that you really want to know about.  These indicate that you have a cycle.  That is, type A refers to type B and type B also refers to Type A. But, that’s not the end of the story.  A handy pop-up appears when you hover over the cell in question.  It explains the color, the dependency, and provides several interesting links that will teach you more than you want to know about the dependency. You can double-click the problem cells to explode the dependency.  That will show the dependencies on a method-by-method basis allowing you to more easily target and fix the problem.  When you’re done you can click the back button on the toolbar. Dependency Graph The dependency graph is another component provided.  It’s complementary to the dependency matrix, but it isn’t as easy to identify dependency issues using the window. On a positive note, it does provide more information than the matrix. My biggest issue with the dependency graph is determining what is shown.  This was not readily obvious.  I ended up using the navigation buttons to get an acceptable view.  I would have liked to choose what I see. Once you see the types you want you can get a decent idea of coupling strength based on the width of the dependency lines.  Double-arrowed lines are problematic and are shown in red.  The size of the boxes will be related to the metric being displayed.  This is controlled using the Box Size drop-down in the toolbar.  Personally, I don’t find the size of the box to be helpful, so I change it to Constant Font. One nice thing about the display is that you can see the entire path of dependencies when you hover over a type.  This is done by color-coding the dependencies and dependants.  It would be nice if selecting the box for the type would lock the highlighting in place. I did find a perhaps unintended work-around to the color-coding.  You can lock the color-coding in by hovering over the type, right-clicking, and then clicking on the canvas area to clear the pop-up menu.  You can then do whatever with it including saving it to an image file with the color-coding. CQL NDepend uses a code query language (CQL) to work with your code just like it was a database.  CQL cannot be confused with the robustness of T-SQL or even LINQ, but it represents an impressive attempt at providing an expressive way to enumerate and interrogate your code. There are two main windows you’ll use when working with CQL.  The CQL Query Explorer allows you to define what queries (rules) are run as part of a report – I immediately unselected rules that I don’t want in my results.  The CQL Query Edit window is where you can view or author your own rules.  The explorer window is pretty self-explanatory, so I won’t mention it further other than to say that any queries you author will appear in the custom group. Authoring your own queries is really hard to screw-up.  The Intellisense-like pop-ups tell you what you can do while making composition easy.  I was able to create a query within two minutes of playing with the editor.  My query warns if any types that are interfaces don’t start with an “I”. WARN IF Count > 0 IN SELECT TYPES WHERE IsInterface AND !NameLike “I” The results from the CQL Query Edit window are immediate. That fact makes it useful for ad hoc querying.  It’s worth mentioning two things that could make the experience smoother.  First, out of habit from using Visual Studio I expect to be able to scroll and press Tab to select an item in the list (like Intellisense).  You have to press Enter when you scroll to the item you want.  Second, the commands are case-sensitive.  I don’t see a really good reason to enforce that. CQL has a lot of potential not just in enforcing code quality, but also enforcing architectural constraints that your enterprise has defined. Up Next My next update will be the final part of the evaluation.  I will summarize my experience and provide my conclusions on the NDepend add-in. ** View Part 1 of the Evaluation ** ** View Part 2 of the Evaluation ** Disclaimer: Patrick Smacchia contacted me about reviewing NDepend. I received a free license in return for sharing my experiences and talking about the capabilities of the add-in on this site. There is no expectation of a positive review elicited from the author of NDepend.

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• Rebuilding CoasterBuzz, Part II: Hot data objects

  - by Jeff

  This is the second post, originally from my personal blog, in a series about rebuilding one of my Web sites, which has been around for 12 years. More: Part I: Evolution, and death to WCF After the rush to get moving on stuff, I temporarily lost interest. I went almost two weeks without touching the project, in part because the next thing on my backlog was doing up a bunch of administrative pages. So boring. Unfortunately, because most of the site's content is user-generated, you need some facilities for editing data. CoasterBuzz has a database full of amusement parks and roller coasters. The entities enjoy the relationships that you would expect, though they're further defined by "instances" of a coaster, to define one that has moved between parks as one, with different names and operational dates. And of course, there are pictures and news items, too. It's not horribly complex, except when you have to account for a name change and display just the newest name. In all previous versions, data access was straight SQL. As so much of the old code was rooted in 2003, with some changes in 2008, there wasn't much in the way of ORM frameworks going on then. Let me rephrase that, I mostly wasn't interested in ORM's. Since that time, I used a little LINQ to SQL in some projects, and a whole bunch of nHibernate while at Microsoft. Through all of that experience, I have to admit that these frameworks are often a bigger pain in the ass than not. They're great for basic crud operations, but when you start having all kinds of exotic relationships, they get difficult, and generate all kinds of weird SQL under the covers. The black box can quickly turn into a black hole. Sometimes you end up having to build all kinds of new expertise to do things "right" with a framework. Still, despite my reservations, I used the newer version of Entity Framework, with the "code first" modeling, in a science project and I really liked it. Since it's just a right-click away with NuGet, I figured I'd give it a shot here. My initial effort was spent defining the context class, which requires a bit of work because I deviate quite a bit from the conventions that EF uses, starting with table names. Then throw some partial querying of certain tables (where you'll find image data), and you're splitting tables across several objects (navigation properties). I won't go into the details, because these are all things that are well documented around the Internet, but there was a minor learning curve there. The basics of reading data using EF are fantastic. For example, a roller coaster object has a park associated with it, as well as a number of instances (if it was ever relocated), and there also might be a big banner image for it. This is stupid easy to use because it takes one line of code in your repository class, and by the time you pass it to the view, you have a rich object graph that has everything you need to display stuff. Likewise, editing simple data is also, well, simple. For this goodness, thank the ASP.NET MVC framework. The UpdateModel() method on the controllers is very elegant. Remember the old days of assigning all kinds of properties to objects in your Webforms code-behind? What a time consuming mess that used to be. Even if you're not using an ORM tool, having hydrated objects come off the wire is such a time saver. Not everything is easy, though. When you have to persist a complex graph of objects, particularly if they were composed in the user interface with all kinds of AJAX elements and list boxes, it's not just a simple matter of submitting the form. There were a few instances where I ended up going back to "old-fashioned" SQL just in the interest of time. It's not that I couldn't do what I needed with EF, it's just that the efficiency, both my own and that of the generated SQL, wasn't good. Since EF context objects expose a database connection object, you can use that to do the old school ADO.NET stuff you've done for a decade. Using various extension methods from POP Forums' data project, it was a breeze. You just have to stick to your decision, in this case. When you start messing with SQL directly, you can't go back in the same code to messing with entities because EF doesn't know what you're changing. Not really a big deal. There are a number of take-aways from using EF. The first is that you write a lot less code, which has always been a desired outcome of ORM's. The other lesson, and I particularly learned this the hard way working on the MSDN forums back in the day, is that trying to retrofit an ORM framework into an existing schema isn't fun at all. The CoasterBuzz database isn't bad, but there are design decisions I'd make differently if I were starting from scratch. Now that I have some of this stuff done, I feel like I can start to move on to the more interesting things on the backlog. There's a lot to do, but at least it's fun stuff, and not more forms that will be used infrequently.

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• Separating text strings into a table of individual words in SQL via XML.

  - by Phil Factor

  p.MsoNormal {margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; font-size:11.0pt; font-family:"Calibri","sans-serif"; } Nearly nine years ago, Mike Rorke of the SQL Server 2005 XML team blogged ‘Querying Over Constructed XML Using Sub-queries’. I remember reading it at the time without being able to think of a use for what he was demonstrating. Just a few weeks ago, whilst preparing my article on searching strings, I got out my trusty function for splitting strings into words and something reminded me of the old blog. I’d been trying to think of a way of using XML to split strings reliably into words. The routine I devised turned out to be slightly slower than the iterative word chop I’ve always used in the past, so I didn’t publish it. It was then I suddenly remembered the old routine. Here is my version of it. I’ve unwrapped it from its obvious home in a function or procedure just so it is easy to appreciate. What it does is to chop a text string into individual words using XQuery and the good old nodes() method. I’ve benchmarked it and it is quicker than any of the SQL ways of doing it that I know about. Obviously, you can’t use the trick I described here to do it, because it is awkward to use REPLACE() on 1…n characters of whitespace. I’ll carry on using my iterative function since it is able to tell me the location of each word as a character-offset from the start, and also because this method leaves punctuation in (removing it takes time!). However, I can see other uses for this in passing lists as input or output parameters, or as return values.   if exists (Select * from sys.xml_schema_collections where name like 'WordList')   drop XML SCHEMA COLLECTION WordList go create xml schema collection WordList as ' <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="words">        <xs:simpleType>               <xs:list itemType="xs:string" />        </xs:simpleType> </xs:element> </xs:schema>'   go   DECLARE @string VARCHAR(MAX) –we'll get some sample data from the great Ogden Nash Select @String='This is a song to celebrate banks, Because they are full of money and you go into them and all you hear is clinks and clanks, Or maybe a sound like the wind in the trees on the hills, Which is the rustling of the thousand dollar bills. Most bankers dwell in marble halls, Which they get to dwell in because they encourage deposits and discourage withdrawals, And particularly because they all observe one rule which woe betides the banker who fails to heed it, Which is you must never lend any money to anybody unless they don''t need it. I know you, you cautious conservative banks! If people are worried about their rent it is your duty to deny them the loan of one nickel, yes, even one copper engraving of the martyred son of the late Nancy Hanks; Yes, if they request fifty dollars to pay for a baby you must look at them like Tarzan looking at an uppity ape in the jungle, And tell them what do they think a bank is, anyhow, they had better go get the money from their wife''s aunt or ungle. But suppose people come in and they have a million and they want another million to pile on top of it, Why, you brim with the milk of human kindness and you urge them to accept every drop of it, And you lend them the million so then they have two million and this gives them the idea that they would be better off with four, So they already have two million as security so you have no hesitation in lending them two more, And all the vice-presidents nod their heads in rhythm, And the only question asked is do the borrowers want the money sent or do they want to take it withm. Because I think they deserve our appreciation and thanks, the jackasses who go around saying that health and happi- ness are everything and money isn''t essential, Because as soon as they have to borrow some unimportant money to maintain their health and happiness they starve to death so they can''t go around any more sneering at good old money, which is nothing short of providential. '   –we now turn it into XML declare @xml_data xml(WordList)  set @xml_data='<words>'+ replace(@string,'&', '&amp;')+'</words>'    select T.ref.value('.', 'nvarchar(100)')  from (Select @xml_data.query('                      for $i in data(/words) return                      element li { $i }               '))  A(list) cross apply A.List.nodes('/li') T(ref)     …which gives (truncated, of course)…

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• Android - How do I load a contact Photo?

  - by PaulH

  I'm having trouble loading a photo for a contact in Android. I've googled for an answer, but so far have come up empty. Does anyone have an example of querying for a Contact, then loading the Photo? So, given a contactUri which comes from an Activity result called using startActivityForResult(new Intent(Intent.ACTION_PICK,ContactsContract.CommonDataKinds.Phone.CONTENT_URI),PICK_CONTACT_REQUEST) is: content://com.android.contacts/data/1557 The loadContact(..) works fine. However when I call the getPhoto(...) method, I get a null value for the photo InputStream. It is also confusing because the URI values are different. The contactPhotoUri evaluates to: content://com.android.contacts/contacts/1557 See the comments inline in the code below. class ContactAccessor { /** * Retrieves the contact information. */ public ContactInfo loadContact(ContentResolver contentResolver, Uri contactUri) { //contactUri --> content://com.android.contacts/data/1557 ContactInfo contactInfo = new ContactInfo(); // Load the display name for the specified person Cursor cursor = contentResolver.query(contactUri, new String[]{Contacts._ID, Contacts.DISPLAY_NAME, Phone.NUMBER, Contacts.PHOTO_ID}, null, null, null); try { if (cursor.moveToFirst()) { contactInfo.setId(cursor.getLong(0)); contactInfo.setDisplayName(cursor.getString(1)); contactInfo.setPhoneNumber(cursor.getString(2)); } } finally { cursor.close(); } return contactInfo; // <-- returns info for contact } public Bitmap getPhoto(ContentResolver contentResolver, Long contactId) { Uri contactPhotoUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, contactId); // contactPhotoUri --> content://com.android.contacts/contacts/1557 InputStream photoDataStream = Contacts.openContactPhotoInputStream(contentResolver,contactPhotoUri); // <-- always null Bitmap photo = BitmapFactory.decodeStream(photoDataStream); return photo; } public class ContactInfo { private long id; private String displayName; private String phoneNumber; private Uri photoUri; public void setDisplayName(String displayName) { this.displayName = displayName; } public String getDisplayName() { return displayName; } public void setPhoneNumber(String phoneNumber) { this.phoneNumber = phoneNumber; } public String getPhoneNumber() { return phoneNumber; } public Uri getPhotoUri() { return this.photoUri; } public void setPhotoUri(Uri photoUri) { this.photoUri = photoUri; } public long getId() { return this.id; } public void setId(long id) { this.id = id; } } } Clearly, I'm doing something wrong here, but I can't seem to figure out what the problem is. Thanks.

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• Getting output parameter(SYS_REFCURSOR) from Oracle stored procedure in iBATIS 3(by using annotation

  - by yjacket

  I got an example how to call oracle SP in iBATIS 3 without a map file. And now I understand how to call it. But I got another problem that how to get a result from output parameter(Oracle cursor). A part of exception messages is "There is no setter for property named 'rs' in 'class java.lang.Class". Below is my code. Does anyone can help me? Oracle Stored Procedure: CREATE OR REPLACE PROCEDURE getProducts ( rs OUT SYS_REFCURSOR ) IS BEGIN OPEN rs FOR SELECT * FROM Products; END getProducts; Interface: public interface ProductMapper { @Select("call getProducts(#{rs,mode=OUT,jdbcType=CURSOR})") @Options(statementType = StatementType.CALLABLE) List<Product> getProducts(); } DAO: public class ProductDAO { public List<Product> getProducts() { return mapper.getProducts(); // mapper is ProductMapper } } Full Error Message: Exception in thread "main" org.apache.ibatis.exceptions.IbatisException: ### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' ### The error may involve defaultParameterMap ### The error occurred while setting parameters ### Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:61) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:53) at org.apache.ibatis.binding.MapperMethod.executeForList(MapperMethod.java:82) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:63) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:35) at $Proxy8.getList(Unknown Source) at com.dao.ProductDAO.getList(ProductDAO.java:42) at com.Ibatis3Test.main(Ibatis3Test.java:30) Caused by: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:154) at org.apache.ibatis.reflection.wrapper.BeanWrapper.set(BeanWrapper.java:36) at org.apache.ibatis.reflection.MetaObject.setValue(MetaObject.java:120) at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleOutputParameters(FastResultSetHandler.java:69) at org.apache.ibatis.executor.statement.CallableStatementHandler.query(CallableStatementHandler.java:44) at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:55) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:41) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:94) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:72) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:59) ... 7 more Caused by: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.Reflector.getSetInvoker(Reflector.java:300) at org.apache.ibatis.reflection.MetaClass.getSetInvoker(MetaClass.java:97) at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:146) ... 16 more

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• How to get a result from output parameter(SYS_REFCURSOR) of Oracle stored procedure in iBATIS 3(by u

  - by yjacket

  I got an example how to call oracle SP in iBATIS 3 without a map file. And now I understand how to call it. But I got another problem that how to get a result from output parameter(Oracle cursor). A part of exception messages is "There is no setter for property named 'rs' in 'class java.lang.Class". Below is my code. Does anyone can help me? Oracle Stored Procedure: CREATE OR REPLACE PROCEDURE getProducts ( rs OUT SYS_REFCURSOR ) IS BEGIN OPEN rs FOR SELECT * FROM Products; END getProducts; Interface: public interface ProductMapper { @Select("call getProducts(#{rs,mode=OUT,jdbcType=CURSOR})") @Options(statementType = StatementType.CALLABLE) List<Product> getProducts(); } DAO: public class ProductDAO { public List<Product> getProducts() { return mapper.getProducts(); // mapper is ProductMapper } } Full Error Message: Exception in thread "main" org.apache.ibatis.exceptions.IbatisException: ### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' ### The error may involve defaultParameterMap ### The error occurred while setting parameters ### Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:61) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:53) at org.apache.ibatis.binding.MapperMethod.executeForList(MapperMethod.java:82) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:63) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:35) at $Proxy8.getList(Unknown Source) at com.dao.ProductDAO.getList(ProductDAO.java:42) at com.Ibatis3Test.main(Ibatis3Test.java:30) Caused by: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:154) at org.apache.ibatis.reflection.wrapper.BeanWrapper.set(BeanWrapper.java:36) at org.apache.ibatis.reflection.MetaObject.setValue(MetaObject.java:120) at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleOutputParameters(FastResultSetHandler.java:69) at org.apache.ibatis.executor.statement.CallableStatementHandler.query(CallableStatementHandler.java:44) at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:55) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:41) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:94) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:72) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:59) ... 7 more Caused by: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.Reflector.getSetInvoker(Reflector.java:300) at org.apache.ibatis.reflection.MetaClass.getSetInvoker(MetaClass.java:97) at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:146) ... 16 more

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• PostgreSQL to Data-Warehouse: Best approach for near-real-time ETL / extraction of data

  - by belvoir

  Background: I have a PostgreSQL (v8.3) database that is heavily optimized for OLTP. I need to extract data from it on a semi real-time basis (some-one is bound to ask what semi real-time means and the answer is as frequently as I reasonably can but I will be pragmatic, as a benchmark lets say we are hoping for every 15min) and feed it into a data-warehouse. How much data? At peak times we are talking approx 80-100k rows per min hitting the OLTP side, off-peak this will drop significantly to 15-20k. The most frequently updated rows are ~64 bytes each but there are various tables etc so the data is quite diverse and can range up to 4000 bytes per row. The OLTP is active 24x5.5. Best Solution? From what I can piece together the most practical solution is as follows: Create a TRIGGER to write all DML activity to a rotating CSV log file Perform whatever transformations are required Use the native DW data pump tool to efficiently pump the transformed CSV into the DW Why this approach? TRIGGERS allow selective tables to be targeted rather than being system wide + output is configurable (i.e. into a CSV) and are relatively easy to write and deploy. SLONY uses similar approach and overhead is acceptable CSV easy and fast to transform Easy to pump CSV into the DW Alternatives considered .... Using native logging (http://www.postgresql.org/docs/8.3/static/runtime-config-logging.html). Problem with this is it looked very verbose relative to what I needed and was a little trickier to parse and transform. However it could be faster as I presume there is less overhead compared to a TRIGGER. Certainly it would make the admin easier as it is system wide but again, I don't need some of the tables (some are used for persistent storage of JMS messages which I do not want to log) Querying the data directly via an ETL tool such as Talend and pumping it into the DW ... problem is the OLTP schema would need tweaked to support this and that has many negative side-effects Using a tweaked/hacked SLONY - SLONY does a good job of logging and migrating changes to a slave so the conceptual framework is there but the proposed solution just seems easier and cleaner Using the WAL Has anyone done this before? Want to share your thoughts?

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• Managing database connections in an Android Activity

  - by Daniel Lew

  I have an application with a ListActivity that uses a CursorAdapter as its adapter. The ListActivity opens the database and does the querying for the CursorAdapter, which is all well and good, but I am having issues with figuring out when to close both the Cursor and the SQLiteDatabase. The way things are handled right now, if the user finishes the activity, I close the database and the cursor. However, this still ends up with the DalvikVM warning me that I've left a database open - for example, if the user hits the "home" button (leaving the activity in the task's stack), rather than the "back" button. If I close them during pause and then re-query during resume, then I don't get any errors, but then a user cannot return to the list without it requerying (and thus losing the user's place in the list). By this I mean, the user can click on any item in the list and open a new activity based on it, but will often want to hit "back" afterwards and return to the same place on the list. If I requery, then I cannot return the user back to the correct spot. What is the proper way to handle this issue? I want the list to remain scrolled properly, but I don't want the VM to keep complaining about unclosed databases. Edit: Here's a general outline of how I handle the code at the moment: public class MyListActivity extends ListActivity { private Cursor mCursor; private CursorAdapter mAdapter; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mAdapter = new MyCursorAdapter(this); setListAdapter(mAdapter); } protected void onPause() { super.onPause(); if (isFinishing()) { mCursor.close(); } } protected void onDestroy() { super.onDestroy(); mCursor.close(); } private void updateQuery() { // If we had a cursor open before, close it. if (mCursor != null) { mCursor.close(); } MyDbHelper dbHelper = new MyDbHelper(this); SQLiteDatabase db = dbHelper.getReadableDatabase(); mCursor = db.query(...); mAdapter.changeCursor(mCursor); db.close(); } } updateQuery() can be called multiple times because the user can filter the results via menu items (I left this part out of the code, as the problem still occurs even if the user does no filtering). Again, the issue is that when I hit home I get leak errors. Yet, after going home, I can go back to the app and find my list again - cursor fully intact.

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• Getting authentication token after a HttpSendRequest

  - by Jessica

  The following code will log in my application to a server. That server will return an authentication token if the login is successful. I need to use that token to query the server for information. egressMsg := pchar('email='+LabeledEdit1.text+'&&password='+MaskEdit1.Text+#0); egressMsg64 := pchar(Encode64(egressMsg)); Reserved := 0; // open connection hInternetConn := InternetOpen('MyApp', INTERNET_OPEN_TYPE_PRECONFIG, NIL, NIL, 0); if hInternetConn = NIL then begin ShowMessage('Error opening internet connection'); exit; end; // connect hHttpSession := InternetConnect(hInternetConn, 'myserver.com', INTERNET_DEFAULT_HTTP_PORT, '', '', INTERNET_SERVICE_HTTP, 0, 0); if hHttpSession = NIL then begin ShowMessage('Error connecting'); exit; end; // send request hHttpRequest := HttpOpenRequest(hHttpSession, 'POST', '/myapp/login', NIL, NIL, NIL, 0, 0); if hHttpRequest = NIL then begin ShowMessage('Error opening request'); exit; end; label2.caption := egressMsg64 + ' '+inttostr(length(egressMsg64)); res := HttpSendRequest(hHttpRequest, Nil, DWORD(-1), egressMsg64, length(egressMsg64)); if not res then begin ShowMessage('Error sending request ' + inttostr(GetLastError)); exit; end; BufferSize := Length(infoBuffer); res := HttpQueryInfo(hHttpRequest, HTTP_QUERY_STATUS_CODE, @infoBuffer, BufferSize, Reserved); if not res then begin ShowMessage('Error querrying request ' + inttostr(GetLastError)); exit; end; reply := infoBuffer; Memo1.Lines.Add(reply); if reply <> '200' then begin //error here end; // how to I get the token here!!!! InternetCloseHandle(hHttpRequest); InternetCloseHandle(hHttpSession); InternetCloseHandle(hInternetConn); How do I get that token? I tried querying the cookie, I tried InternetGetCookie() and a lot more. Code is appreciated Thanks jess EDIT I found that if you use InternetReadFile you can get that token. However that token comes out as an array of bytes. It's hard to use it later to send it to the server... anyone knows how to convert an array of bytes to pchar or string?

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• Linq to List and IEnumerable issues

  - by Otaku

  I am querying an HTML file with Linq. It looks something like this: <html> <body> <div class="Players"> <div class="role">Goalies</div> <div class="name">John Smith</div> <div class="name">Shawn Xie</div> <div class="role">Right Wings</div> <div class="name">Jack Davis</div> <div class="name">Carl Yuns</div> <div class="name">Wayne Gortonia</div> <div class="role">Centers</div> <div class="name">Lutz Gaspy</div> <div class="name">John Jacobs</div> </div </html> </body> What I'm trying to do is create a list of these folks like in a list of a structure called Players: Structure Players Public Name As String Public Position As String End Structure But I've quickly found out I don't really know what I'm doing when it comes to Linq. I've got this far my my queries: Dim goalieList = From d In player.Elements _ Where d.Value = "Goalies" _ Select From g In d.ElementsAfterSelf _ Take While (g.@class <> "role") _ Select New Players With {.Position = "Goalie", _ .Name = g.Value} Dim centersList = From d In player.Elements _ Where d.Value = "Centers" _ Select From g In d.ElementsAfterSelf _ Take While (g.@class <> "role") _ Select New Players With {.Position = "Centers", _ .Name = g.Value} Which gets me down to the the players by position, but then I can't do much with this afterwards the result type is System.Collections.Generic.IEnumerable(Of System.Collections.Generic.IEnumerable(Of Player)) What I want to do is add these two results to a new list, like: Dim playersList As List(Of Players) = Nothing playersList.AddRange(centersList) playersList.AddRange(goalieList) So that I can then query the list and use it. But it kicks the error: Unable to cast object of type 'WhereSelectEnumerableIterator2[System.Xml.Linq.XElement,System.Collections.Generic.IEnumerable1[Players]]' to type 'System.Collections.Generic.IEnumerable`1[Players]' As you can see, I may really have no idea how to work with all these objects/classes. Does anyone have any insight on what I may be doing wrong and how I can resolve it? RESOLVED: The Linq query needs to return a single iEnumerable, like this: Dim goalieList = From l In _ (From d In players.Elements _ Where d.Value = "Goalies" _ Select d.ElementsAfterSelf.TakeWhile(Function(f) f.@class <> "role")) _ Select New Players With {.Position = "Goalie", .Name = l.Value} and then use goalieList.ToList

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• link_to passing paramater and display problem - tag feature - Ruby on Rails

  - by bgadoci

  I have gotten a great deal of help from KandadaBoggu on my last question and very very thankful for that. As we were getting buried in the comments I wanted to break this part out. I am attempting to create a tag feature on the rails blog I am developing. The relationship is Post has_many :tags and Tag belongs_to :post. Adding and deleting tags to posts are working great. In my /view/posts/index.html.erb I have a section called tags where I am successfully querying the Tags table, grouping them and displaying the count next to the tag_name (as a side note, I mistakenly called the column containing the tag name, 'tag_name' instead of just 'name' as I should have) . In addition the display of these groups are a link that is referencing the index method in the PostsController. That is where the problem is. When you navigate to /posts you get an error because there is no parameter being passed (without clicking the tag group link). I have the .empty? in there so not sure what is going wrong here. Here is the error and code: Error You have a nil object when you didn't expect it! You might have expected an instance of Array. The error occurred while evaluating nil.empty? /views/posts/index.html.erb <% @tag_counts.each do |tag_name, tag_count| %> <tr> <td><%= link_to(tag_name, posts_path(:tag_name => tag_name)) %></td> <td>(<%=tag_count%>)</td> </tr> <% end %> PostsController def index @tag_counts = Tag.count(:group => :tag_name, :order => 'updated_at DESC', :limit => 10) @posts=Post.all(:joins => :tags,:conditions=>(params[:tag_name].empty? ? {}: { :tags => { :tag_name => params[:tag_name] }} ) ) respond_to do |format| format.html # index.html.erb format.xml { render :xml => @posts } format.json { render :json => @posts } format.atom end end

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• Eclipselink read complex object model in an ordered way

  - by Raven

  Hi, I need to read a complex model in an ordered way with eclipselink. The order is mandantory because it is a huge database and I want to have an output of a small portion of the database in a jface tableview. Trying to reorder it in the loading/quering thread takes too long and ordering it in the LabelProvider blocks the UI thread too much time, so I thought if Eclipselink could be used that way, that the database will order it, it might give me the performance I need. Unfortunately the object model can not be changed :-( The model is something like: @SuppressWarnings("serial") @Entity public class Thing implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; @OneToMany(cascade=CascadeType.ALL) @PrivateOwned private List<Property> properties = new ArrayList<Property>(); ... // getter and setter following here } public class Property implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; @OneToOne private Item item; private String value; ... // getter and setter following here } public class Item implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; .... // getter and setter following here } // Code end In the table view the y-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Thing m ORDER BY m.name ASC"); using the "name" attribute from the Thing objects as label. In the table view the x-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Item m ORDER BY m.name ASC"); using the "name" attribute from the Item objects as label. Each cell has the value Things.getProperties().get[x].getValue() Unfortunately the list "properties" is not ordered, so the combination of cell value and x-axis column number (x) is not necessarily correct. Therefore I need to order the list "properties" in the same way as I ordered the labeling of the x-axis. And exactly this is the thing I dont know how it is done. So querying for the Thing objects should return the list "properties" "ORDER BY name ASC" but of the "Item"s objects. My ideas are something like having a query with two JOINs. Joing Things with Property and with Item but somehow I was unable to get it to work yet. Thank you for your help and your ideas to solve this riddle.

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• How to optimize Core Data query for full text search

  - by dk

  Can I optimize a Core Data query when searching for matching words in a text? (This question also pertains to the wisdom of custom SQL versus Core Data on an iPhone.) I'm working on a new (iPhone) app that is a handheld reference tool for a scientific database. The main interface is a standard searchable table view and I want as-you-type response as the user types new words. Words matches must be prefixes of words in the text. The text is composed of 100,000s of words. In my prototype I coded SQL directly. I created a separate "words" table containing every word in the text fields of the main entity. I indexed words and performed searches along the lines of SELECT id, * FROM textTable JOIN (SELECT DISTINCT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) ON id=textTableId LIMIT 50 This runs very fast. Using an IN would probably work just as well, i.e. SELECT * FROM textTable WHERE id IN (SELECT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) LIMIT 50 The LIMIT is crucial and allows me to display results quickly. I notify the user that there are too many to display if the limit is reached. This is kludgy. I've spent the last several days pondering the advantages of moving to Core Data, but I worry about the lack of control in the schema, indexing, and querying for an important query. Theoretically an NSPredicate of textField MATCHES '.*\bfoo.*' would just work, but I'm sure it will be slow. This sort of text search seems so common that I wonder what is the usual attack? Would you create a words entity as I did above and use a predicate of "word BEGINSWITH 'foo'"? Will that work as fast as my prototype? Will Core Data automatically create the right indexes? I can't find any explicit means of advising the persistent store about indexes. I see some nice advantages of Core Data in my iPhone app. The faulting and other memory considerations allow for efficient database retrievals for tableview queries without setting arbitrary limits. The object graph management allows me to easily traverse entities without writing lots of SQL. Migration features will be nice in the future. On the other hand, in a limited resource environment (iPhone) I worry that an automatically generated database will be bloated with metadata, unnecessary inverse relationships, inefficient attribute datatypes, etc. Should I dive in or proceed with caution?

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• Should an event-sourced aggregate root have query access to the event sourcing repository?

  - by JD Courtoy

  I'm working on an event-sourced CQRS implementation, using DDD in the application / domain layer. I have an object model that looks like this: public class Person : AggregateRootBase { private Guid? _bookingId; public Person(Identification identification) { Apply(new PersonCreatedEvent(identification)); } public Booking CreateBooking() { // Enforce Person invariants var booking = new Booking(); Apply(new PersonBookedEvent(booking.Id)); return booking; } public void Release() { // Enforce Person invariants // Should we load the booking here from the aggregate repository? // We need to ensure that booking is released as well. var booking = BookingRepository.Load(_bookingId); booking.Release(); Apply(new PersonReleasedEvent(_bookingId)); } [EventHandler] public void Handle(PersonBookedEvent @event) { _bookingId = @event.BookingId; } [EventHandler] public void Handle(PersonReleasedEvent @event) { _bookingId = null; } } public class Booking : AggregateRootBase { private DateTime _bookingDate; private DateTime? _releaseDate; public Booking() { //Enforce invariants Apply(new BookingCreatedEvent()); } public void Release() { //Enforce invariants Apply(new BookingReleasedEvent()); } [EventHandler] public void Handle(BookingCreatedEvent @event) { _bookingDate = SystemTime.Now(); } [EventHandler] public void Handle(BookingReleasedEvent @event) { _releaseDate = SystemTime.Now(); } // Some other business activities unrelated to a person } With my understanding of DDD so far, both Person and Booking are seperate aggregate roots for two reasons: There are times when business components will pull Booking objects separately from the database. (ie, a person that has been released has a previous booking modified due to incorrect information). There should not be locking contention between Person and Booking whenever a Booking needs to be updated. One other business requirement is that a Booking can never occur for a Person more than once at a time. Due to this, I'm concerned about querying the query database on the read side as there could potentially be some inconsistency there (due to using CQRS and having an eventually consistent read database). Should the aggregate roots be allowed to query the event-sourced backing store for objects (lazy-loading them as needed)? Are there any other avenues of implementation that would make more sense?

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• Hibernate annotated many-to-one not adding child to parent Collection

  - by Rob Hruska

  I have the following annotated Hibernate entity classes: @Entity public class Cat { @Column(name = "ID") @GeneratedValue(strategy = GenerationType.AUTO) @Id private Long id; @OneToMany(mappedBy = "cat", cascade = CascadeType.ALL, fetch = FetchType.EAGER) private Set<Kitten> kittens = new HashSet<Kitten>(); public void setId(Long id) { this.id = id; } public Long getId() { return id; } public void setKittens(Set<Kitten> kittens) { this.kittens = kittens; } public Set<Kitten> getKittens() { return kittens; } } @Entity public class Kitten { @Column(name = "ID") @GeneratedValue(strategy = GenerationType.AUTO) @Id private Long id; @ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER) private Cat cat; public void setId(Long id) { this.id = id; } public Long getId() { return id; } public void setCat(Cat cat) { this.cat = cat; } public Cat getCat() { return cat; } } My intention here is a bidirectional one-to-many/many-to-one relationship between Cat and Kitten, with Kitten being the "owning side". What I want to happen is when I create a new Cat, followed by a new Kitten referencing the Cat, the Set of kittens on my Cat should contain the new Kitten. However, this does not happen in the following test: @Test public void testAssociations() { Session session = HibernateUtil.getSessionFactory().getCurrentSession(); Transaction tx = session.beginTransaction(); Cat cat = new Cat(); session.save(cat); Kitten kitten = new Kitten(); kitten.setCat(cat); session.save(kitten); tx.commit(); assertNotNull(kitten.getCat()); assertEquals(cat.getId(), kitten.getCat().getId()); assertTrue(cat.getKittens().size() == 1); // <-- ASSERTION FAILS assertEquals(kitten, new ArrayList<Kitten>(cat.getKittens()).get(0)); } Even after re-querying the Cat, the Set is still empty: // added before tx.commit() and assertions cat = (Cat)session.get(Cat.class, cat.getId()); Am I expecting too much from Hibernate here? Or is the burden on me to manage the Collection myself? The (Annotations) documentation doesn't make any indication that I need to create convenience addTo*/removeFrom* methods on my parent object. Can someone please enlighten me on what my expectations should be from Hibernate with this relationship? Or if nothing else, point me to the correct Hibernate documentation that tells me what I should be expecting to happen here. What do I need to do to make the parent Collection automatically contain the child Entity?

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• Data denormalization and C# objects DB serialization

  - by Robert Koritnik

  I'm using a DB table with various different entities. This means that I can't have an arbitrary number of fields in it to save all kinds of different entities. I want instead save just the most important fields (dates, reference IDs - kind of foreign key to various other tables, most important text fields etc.) and an additional text field where I'd like to store more complete object data. the most obvious solution would be to use XML strings and store those. The second most obvious choice would be JSON, that usually shorter and probably also faster to serialize/deserialize... And is probably also faster. But is it really? My objects also wouldn't need to be strictly serializable, because JsonSerializer is usually able to serialize anything. Even anonymous objects, that may as well be used here. What would be the most optimal solution to solve this problem? Additional info My DB is highly normalised and I'm using Entity Framework, but for the purpose of having external super-fast fulltext search functionality I'm sacrificing a bit DB denormalisation. Just for the info I'm using SphinxSE on top of MySql. Sphinx would return row IDs that I would use to fast query my index optimised conglomerate table to get most important data from it much much faster than querying multiple tables all over my DB. My table would have columns like: RowID (auto increment) EntityID (of the actual entity - but not directly related because this would have to point to different tables) EntityType (so I would be able to get the actual entity if needed) DateAdded (record timestamp when it's been added into this table) Title Metadata (serialized data related to particular entity type) This table would be indexed with SPHINX indexer. When I would search for data using this indexer I would provide a series of EntityIDs and a limit date. Indexer would have to return a very limited paged amount of RowIDs ordered by DateAdded (descending). I would then just join these RowIDs to my table and get relevant results. So this won't actually be full text search but a filtering search. Getting RowIDs would be very fast this way and getting results back from the table would be much faster than comparing EntityIDs and DateAdded comparisons even though they would be properly indexed.

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• Eclipselink read complex oject model in an ordered way

  - by Raven

  Hi, I need to read a complex model in an ordered way with eclipselink. The order is mandantory because it is a huge database and I want to have an output of a small portion of the database in a jface tableview. Trying to reorder it in the loading/quering thread takes too long and ordering it in the LabelProvider blocks the UI thread too much time, so I thought if Eclipselink could be used that way, that the database will order it, it might give me the performance I need. Unfortunately the object model can not be changed :-( The model is something like: @SuppressWarnings("serial") @Entity public class Thing implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; @OneToMany(cascade=CascadeType.ALL) @PrivateOwned private List<Property> properties = new ArrayList<Property>(); ... // getter and setter following here } public class Property implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; @OneToOne private Item item; private String value; ... // getter and setter following here } public class Item implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; .... // getter and setter following here } // Code end In the table view the y-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Thing m ORDER BY m.name ASC"); using the "name" attribute from the Thing objects as label. In the table view the x-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Item m ORDER BY m.name ASC"); using the "name" attribute from the Item objects as label. Each cell has the value Things.getProperties().get[x].getValue() Unfortunately the list "properties" is not ordered, so the combination of cell value and x-axis column number (x) is not necessarily correct. Therefore I need to order the list "properties" in the same way as I ordered the labeling of the x-axis. And exactly this is the thing I dont know how it is done. So querying for the Thing objects should return the list "properties" "ORDER BY name ASC" but of the "Item"s objects. My ideas are something like having a query with two JOINs. Joing Things with Property and with Item but somehow I was unable to get it to work yet. Thank you for your help and your ideas to solve this riddle.

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• System.Net.Dns.GetHostAddresses("")

  - by dbasnett

  Yesterday s**ked, and today ain't (sic) looking better. I have an application I have been working on and it can be slow to start when my ISP is down because of DNS. My ISP was down for 3 hours yesterday, so I didn't think much about this piece of code I had added, until I found that it is always slow to start. This code is supposed to return your IP address and my reading of the link suggests that should be immediate, but it isn't, at least on my machine. Oh, and yesterday before the internet went down, I upgraded (oymoron) to XP SP3, and have had other problems. So my questions / request: 1. Am I doing this right? 2. If you run this on your machine does it take 39 seconds to return your IP address? It does on mine. One other note, I did a packet capture and the first request did NOT go on the wire, but the second did, and was answered quickly. So the question is what happened in XP SP3 that I am missing, besides a brain. One last note. If I resolve a FQDN all is well. Public Class Form1 'http://msdn.microsoft.com/en-us/library/system.net.dns.gethostaddresses.aspx ' 'excerpt 'The GetHostAddresses method queries a DNS server 'for the IP addresses associated with a host name. ' 'If hostNameOrAddress is an IP address, this address 'is returned without querying the DNS server. ' 'When an empty string is passed as the host name, 'this method returns the IPv4 addresses of the local host Private Sub Button1_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button1.Click Dim stpw As New Stopwatch stpw.Reset() stpw.Start() 'originally Dns.GetHostEntry, but slow also Dim myIPs() As System.Net.IPAddress = System.Net.Dns.GetHostAddresses("") stpw.Stop() Debug.WriteLine("'" & stpw.Elapsed.TotalSeconds) If myIPs.Length > 0 Then Debug.WriteLine("'" & myIPs(0).ToString) 'debug '39.8990525 '192.168.1.2 stpw.Reset() stpw.Start() 'originally Dns.GetHostEntry, but slow also myIPs = System.Net.Dns.GetHostAddresses("www.vbforums.com") stpw.Stop() Debug.WriteLine("'" & stpw.Elapsed.TotalSeconds) If myIPs.Length > 0 Then Debug.WriteLine("'" & myIPs(0).ToString) 'debug '0.042212 '63.236.73.220 End Sub End Class

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• iPhone: Speeding up a search that's polling 17,000 Core Data objects

  - by randombits

  I have a class that conforms to UISearchDisplayDelegate and contains a UISearchBar. This view is responsible for allowing the user to poll a store of about 17,000 objects that are currently managed by Core Data. Everytime the user types in a character, I created an instance of a SearchOperation (subclasses NSOperation) that queries Core Data to find results that might match the search. The code in the search controller looks something like: - (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope { // Update the filtered array based on the search text and scope in a secondary thread if ([searchText length] < 3) { [filteredList removeAllObjects]; // First clear the filtered array. [self setFilteredList:NULL]; [self.tableView reloadData]; return; } NSDictionary *searchdict = [NSDictionary dictionaryWithObjectsAndKeys:scope, @"scope", searchText, @"searchText", nil]; [aSearchQueue cancelAllOperations]; SearchOperation *searchOp = [[SearchOperation alloc] initWithDelegate:self dataDict:searchdict]; [aSearchQueue addOperation:searchOp]; } And my search is rather straight forward. SearchOperation is a subclass of NSOperation. I overwrote the main method with the following code: - (void)main { if ([self isCancelled]) { return; } NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext]; NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; [fetchRequest setEntity:entity]; NSPredicate *predicate = NULL; predicate = [NSPredicate predicateWithFormat:@"(someattr contains[cd] %@)", searchText]; [fetchRequest setPredicate:predicate]; NSError *error = NULL; NSArray *fetchResults = [managedObjectContext executeFetchRequest:fetchRequest error:&error]; [fetchRequest release]; if (self.delegate != nil) [self.delegate didFinishSearching:fetchResults]; [pool drain]; } This code works, but it has several issues. It's slow. Even though I have the search happening in a separate thread other than the UI thread, querying 17,000 objects is clearly not optimal. If I'm not careful, crashes can happen. I set the max concurrent searches in my NSOperationQueue to 1 to avoid this. What else can I do to make this search faster? I think preloading all 17,000 objects into memory might be risky. There has to be a smarter way to conduct this search to give results back to the user faster.

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• Reduce Multiple Errors logging in sysssislog

  - by Akshay

  Need help. I am trying to automate error notifications to be sent in mailers. For that I am querying the sysssislog table. I have pasted an "Execute SQl task" on the package event handler "On error". For testing purpose, I am deliberately trying to load duplicate keys in a table which consists of a Primary key column(so as to get an error). But instead of having just one error, "Violation of primary key constraint", SSIS records 3 in the table. PFA the screenshot as well. How can i restrict the tool to log only one error and not multiple ??? Package Structure. Package ("On error Event handler") - DFT - Oledb Source - Oledb Destination SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80004005. An OLE DB record is available. Source: "Microsoft SQL Server Native Client 10.0" Hresult: 0x80004005 Description: "The statement has been terminated.". An OLE DB record is available. Source: "Microsoft SQL Server Native Client 10.0" Hresult: 0x80004005 Description: "Violation of PRIMARY KEY constraint 'PK_SalesPerson_SalesPersonID'. Cannot insert duplicate key in object 'dbo.SalesPerson'.". SSIS Error Code DTS_E_INDUCEDTRANSFORMFAILUREONERROR. The "input "OLE DB Destination Input" (56)" failed because error code 0xC020907B occurred, and the error row disposition on "input "OLE DB Destination Input" (56)" specifies failure on error. An error occurred on the specified object of the specified component. There may be error messages posted before this with more information about the failure. SSIS Error Code DTS_E_PROCESSINPUTFAILED. The ProcessInput method on component "OLE DB Destination" (43) failed with error code 0xC0209029 while processing input "OLE DB Destination Input" (56). The identified component returned an error from the ProcessInput method. The error is specific to the component, but the error is fatal and will cause the Data Flow task to stop running. There may be error messages posted before this with more information about the failure. Please guide me. Your help is very much appreciated. Thanks

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• how can I get data in the table cell that is checked after submit

  - by arnold

  can someone give me help, please. here's my basic html <form action="addSomething.php" method="POST"> <table> <tr> <th>Add Data</th> <th>Description</th> <th>Quantity</th> </tr> <tr> <td><input type="checkbox" name="data[]" value="sample1" /> </td> <td class="desc">Newbie</td> <td>2</td> </tr> <tr> <td><input type="checkbox" name="data[]" value="sample1" /> </td> <td class="desc">Pro</td> <td>1</td> </tr> <tr> <td><input type="checkbox" name="data[]" value="sample1"/> </td> <td class="desc" > Master </td> <td>1</td> </tr> <br/> <input type="submit" name="add" value="SUBMIT"/> ..... how can I get the one with the class "desc" and the column for quantity that is checked after submitting the form because the only I can add when querying in mysql is the value of checkbox but I want also the value of the data in "Description" column and "Quantity" column In my addSomething.php the code I have is if(isset($_POST['add'])) { foreach($_POST['data'] as $value) { $sql = "INSERT INTO tablename (column1) VALUES('$value');" //query stuff } } what I will do , Any hints guys?

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• How to designing a generic databse whos layout may change over time?

  - by mawg

  Here's a tricky one - how do I programatically create and interrogate a database who's contents I can't really foresee? I am implementing a generic input form system. The user can create PHP forms with a WYSIWYG layout and use them for any purpose he wishes. He can also query the input. So, we have three stages: a form is designed and generated. This is a one-off procedure, although the form can be edited later. This designs the database. someone or several people make use of the form - say for daily sales reports, stock keeping, payroll, etc. Their input to the forms is written to the database. others, maybe management, can query the database and generate reports. Since these forms are generic, I can't predict the database structure - other than to say that it will reflect HTML form fields and consist of a the data input from collection of edit boxes, memos, radio buttons and the like. Questions and remarks: A) how can I best structure the database, in terms of tables and columns? What about primary keys? My first thought was to use the control name to identify each column, then I realized that the user can edit the form and rename, so that maybe "name" becomes "employee" or "wages" becomes ":salary". I am leaning towards a unique number for each. B) how best to key the rows? I was thinking of a timestamp to allow me to query and a column for the row Id from A) C) I have to handle column rename/insert/delete. Foe deletion, I am unsure whether to delete the data from the database. Even if the user is not inputting it from the form any more he may wish to query what was previously entered. Or there may be some legal requirements to retain the data. Any gotchas in column rename/insert/delete? D) For the querying, I can have my PHP interrogate the database to get column names and generate a form with a list where each entry has a database column name, a checkbox to say if it should be used in the query and, based on column type, some selection criteria. That ought to be enough to build searches like "position = 'senior salesman' and salary 50k". E) I probably have to generate some fancy charts - graphs, histograms, pie charts, etc for query results of numerical data over time. I need to find some good FOSS PHP for this. F) What else have I forgotten? This all seems very tricky to me, but I am database n00b - maybe it is simple to you gurus?

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• In a DDD approach, is this example modelled correctly?

  - by Tag

  Just created an acc on SO to ask this :) Assuming this simplified example: building a web application to manage projects... The application has the following requirements/rules. 1) Users should be able to create projects inserting the project name. 2) Project names cannot be empty. 3) Two projects can't have the same name. I'm using a 4-layered architecture (User Interface, Application, Domain, Infrastructure). On my Application Layer i have the following ProjectService.cs class: public class ProjectService { private IProjectRepository ProjectRepo { get; set; } public ProjectService(IProjectRepository projectRepo) { ProjectRepo = projectRepo; } public void CreateNewProject(string name) { IList<Project> projects = ProjectRepo.GetProjectsByName(name); if (projects.Count > 0) throw new Exception("Project name already exists."); Project project = new Project(name); ProjectRepo.InsertProject(project); } } On my Domain Layer, i have the Project.cs class and the IProjectRepository.cs interface: public class Project { public int ProjectID { get; private set; } public string Name { get; private set; } public Project(string name) { ValidateName(name); Name = name; } private void ValidateName(string name) { if (name == null || name.Equals(string.Empty)) { throw new Exception("Project name cannot be empty or null."); } } } public interface IProjectRepository { void InsertProject(Project project); IList<Project> GetProjectsByName(string projectName); } On my Infrastructure layer, i have the implementation of IProjectRepository which does the actual querying (the code is irrelevant). I don't like two things about this design: 1) I've read that the repository interfaces should be a part of the domain but the implementations should not. That makes no sense to me since i think the domain shouldn't call the repository methods (persistence ignorance), that should be a responsability of the services in the application layer. (Something tells me i'm terribly wrong.) 2) The process of creating a new project involves two validations (not null and not duplicate). In my design above, those two validations are scattered in two different places making it harder (imho) to see whats going on. So, my question is, from a DDD perspective, is this modelled correctly or would you do it in a different way?

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• stored as array understanding mongoid

  - by Gagan

  Hello frens, This is not a problem, but I just want to know stored as array of Mongoid better. I have following code in my model. class Company include Mongoid::Document include Mongoid::Timestamps references_many :people, :stored_as => :array, :inverse_of => :companies end class Person include Mongoid::Document include Sunspot::Mongoid references_many :companies, :stored_as => :array, :inverse_of => :people end Now in Company object we get person_ids as a result of stored_as array and company_ids in Person object. Now initially I inserted lots of person in company and the ids in person_ids fields is huge. Now I deleted most of person from company down to 8 people. Now I don't get why person_ids fields of Company object storing all the deleted ids of person. My console snapshot is follwing ruby-1.9.2-head Company.first.person_ids = [BSON::ObjectId('4d12d2907adf350695000025'), BSON::ObjectId('4d12d2907adf35069500002c'), BSON::ObjectId('4d12d2907adf350695000035'), BSON::ObjectId('4d12d2907adf35069500003f'), BSON::ObjectId('4d12d2907adf350695000048'), BSON::ObjectId('4d12d2907adf350695000052'), BSON::ObjectId('4d12d2907adf350695000059'), BSON::ObjectId('4d12d2907adf350695000062'), BSON::ObjectId('4d12d4017adf35069500008d'), BSON::ObjectId('4d12d4017adf350695000094'), BSON::ObjectId('4d12d4017adf35069500009d'), BSON::ObjectId('4d12d4017adf3506950000a7'), BSON::ObjectId('4d12d4017adf3506950000b0'), BSON::ObjectId('4d12d4017adf3506950000ba'), BSON::ObjectId('4d12d4017adf3506950000c1'), BSON::ObjectId('4d12d4017adf3506950000ca'), BSON::ObjectId('4d12d48a7adf3506950000f5'), BSON::ObjectId('4d12d48a7adf3506950000fc'), BSON::ObjectId('4d12d48a7adf350695000108'), BSON::ObjectId('4d12d48b7adf350695000115'), BSON::ObjectId('4d12d48b7adf350695000121'), BSON::ObjectId('4d12d48b7adf35069500012e'), BSON::ObjectId('4d12d48b7adf350695000135'), BSON::ObjectId('4d12d48b7adf350695000141'), BSON::ObjectId('4d12d53e7adf35069500016f'), BSON::ObjectId('4d12d53e7adf350695000176'), BSON::ObjectId('4d12d53e7adf350695000182'), BSON::ObjectId('4d12d53e7adf35069500018f'), BSON::ObjectId('4d12d53e7adf35069500019b'), BSON::ObjectId('4d12d53f7adf3506950001a8'), BSON::ObjectId('4d12d53f7adf3506950001af'), BSON::ObjectId('4d12d53f7adf3506950001bb'), BSON::ObjectId('4d12d8587adf3506950001e9'), BSON::ObjectId('4d12d8587adf3506950001f0'), BSON::ObjectId('4d12d8587adf3506950001ff'), BSON::ObjectId('4d12d8597adf35069500020f'), BSON::ObjectId('4d12d8597adf35069500021e'), BSON::ObjectId('4d12d8597adf35069500022e'), BSON::ObjectId('4d12d8597adf350695000235'), BSON::ObjectId('4d12d85a7adf350695000244'), BSON::ObjectId('4d12d9587adf35069500025b'), BSON::ObjectId('4d12db8b7adf35069500026a'), BSON::ObjectId('4d12de6f7adf3509c9000024'), BSON::ObjectId('4d12de6f7adf3509c900002b'), BSON::ObjectId('4d12de6f7adf3509c900003a'), BSON::ObjectId('4d12de707adf3509c900004a'), BSON::ObjectId('4d12de707adf3509c9000059'), BSON::ObjectId('4d12de707adf3509c9000069'), BSON::ObjectId('4d12de707adf3509c9000070'), BSON::ObjectId('4d12de717adf3509c900007f'), BSON::ObjectId('4d12e7f27adf350bd2000009'), BSON::ObjectId('4d12e81f7adf350bd2000015'), BSON::ObjectId('4d12e87f7adf350bd2000024'), BSON::ObjectId('4d12e8b87adf350bd200004c'), BSON::ObjectId('4d12e8b97adf350bd2000053'), BSON::ObjectId('4d12e8b97adf350bd200005c'), BSON::ObjectId('4d12e8b97adf350bd2000066'), BSON::ObjectId('4d12e8b97adf350bd200006f'), BSON::ObjectId('4d12e8b97adf350bd2000079'), BSON::ObjectId('4d12e8ba7adf350bd2000080'), BSON::ObjectId('4d12e8ba7adf350bd2000089'), BSON::ObjectId('4d12ee6b7adf350bd2000198'), BSON::ObjectId('4d12ee6b7adf350bd200019f'), BSON::ObjectId('4d12ee6c7adf350bd20001a5'), BSON::ObjectId('4d12ee6c7adf350bd20001ac'), BSON::ObjectId('4d12ee6c7adf350bd20001b2'), BSON::ObjectId('4d12ee6c7adf350bd20001b9'), BSON::ObjectId('4d12ee6c7adf350bd20001c0'), BSON::ObjectId('4d12ee6c7adf350bd20001c6'), BSON::ObjectId('4d141ca57adf35033e00006e'), BSON::ObjectId('4d141ca57adf35033e000075'), BSON::ObjectId('4d1420aa7adf350705000003'), BSON::ObjectId('4d1420aa7adf35070500000a'), BSON::ObjectId('4d1420f47adf350705000011'), BSON::ObjectId('4d1420f57adf350705000015'), BSON::ObjectId('4d1420f57adf350705000018'), BSON::ObjectId('4d1420f57adf35070500001c'), BSON::ObjectId('4d1420f57adf350705000023'), BSON::ObjectId('4d1420f57adf350705000026'), BSON::ObjectId('4d14215f7adf35070500004b'), BSON::ObjectId('4d14215f7adf350705000052'), BSON::ObjectId('4d14215f7adf350705000055'), BSON::ObjectId('4d14215f7adf350705000059'), BSON::ObjectId('4d14215f7adf35070500005c'), BSON::ObjectId('4d14215f7adf350705000060'), BSON::ObjectId('4d14215f7adf350705000067'), BSON::ObjectId('4d14215f7adf35070500006a')] Company.first.people.collect(&:id) = [BSON::ObjectId('4d14215f7adf35070500004b'), BSON::ObjectId('4d14215f7adf350705000052'), BSON::ObjectId('4d14215f7adf350705000055'), BSON::ObjectId('4d14215f7adf350705000059'), BSON::ObjectId('4d14215f7adf35070500005c'), BSON::ObjectId('4d14215f7adf350705000060'), BSON::ObjectId('4d14215f7adf350705000067'), BSON::ObjectId('4d14215f7adf35070500006a')] Isn't the Company.first.person_ids array be only storing the ids shown by Company.first.people.collect(&:id) It would be helpful if some one tell me when to best use stored_as = :array method. Do stored_as = :array increase querying performance? Thanks

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