An attempt to attach an auto-named database for file *.mdf failed

And another catch when using SQL Server Express 2005. There are several posts some are helpful some are not. The scenario I am focussing on here is embedding SQL Server Express 2005 into your .NET application. In that case you'd ship the database files (MDF and LDF) with your application and include them in the setup script as well. The usual question when working with ADO.NET is: How does the connection string look like? In my case I tried a few, and then try to use the following very simple C# code:

1: using(SqlConnection conn = new SqlConnection(connectionString)) {
2:   try {
3:      conn.Open();
4:   }
5:   catch(Exception ex) {
6:   }
7:}

I got an exception in line 3 along the lines

"An attempt to attach an auto-named database for file ###.mdf failed ..."

(note that ### is a place holder for the actual filename). I solved it by using information from MSDN, and the working connection string looked as follows:

Data Source = .\SQLEXPRESS; Integrated Security=true; User Instance=true; AttachDBFilename=DataDirectory\###.mdf; Initial Catalog=###;

Again, ### is a replacement for the actual file name. Using this connection string I can now access the database file in a user instance of SQL Server 2005 Express. Some additional comments:

• The user instance is separate from any SQL Server 2005 Express instance that may be running on the system as well. However, unless you haven't changed any permissions or default settings, even a user without administrative rights can run a program and access a user instance.
• Do not attach the database file at the same time with SQL Server Management Studio Express as you can't attach the same database file to twice to two different SQL Server (Express) instances.
• Always make sure you close the database connection. In the above code this is achived with the using statement as regardless how that block of code is left (exception or normal program flow) the Dispose() method will be called. This will always close the connection, and you have avoided a connection leak.
• If you use a connection string in you application, use the same one for all connections to the same database. If you use different connection strings, e.g. change the order of the parameters in them, these will be considered to be different and a connection pool for each will be created. The connection strings must be the same, every single character.

For more info please also see the link attached to this post. If you can't find it, try the heading!

Windows-Safari

OK, I have downloaded and installed Apple's Safari on my Windows XP notebook. Anything earth shattering? I haven't found it yet, but I guess that's because I have used it only for a short time so far. One thing I have observed: For my taste the usability is behind IE7 or Firefox. But again this might be because I'm biased, spoiled, or it might just be a matter of taste. Maybe I simply can't appreciate the "magic" of Safari. Maybe my expectations were simply too high. I'll give it a few more days, and maybe I'll start to get more into it....

Could not open a connection to SQL Server

Using Visual Studio 2005 I tried to connect to a fresh installation of SQL Server 2005 Express. I encountered the following problem:

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

I tried all the suggestions such as the ones provided by DataMasker but had no luck. But then I found a hint in a discussion forum on DevX that helped me to resolve the issue. Instead of entering just "localhost" for the Server name I used "localhost\SQLExpress" and all the sudden it worked.

With this blog entry I hope that I can save some people's time. Cheers!

"Generating user instances in SQL Server is disabled. Use sp_configure 'user instances enabled' to generate user instances."

Just in case you ran into the same problem: 1. Open the SQL Server Management Studio Express. This is the downloadable program in the same site where you downloaded the SQL Server 2005 express used to manage SQL Server 2005 Express. 2. In the query editor type this text (everything between the double quotes): "exec sp_configure 'user instances enabled', 1" 3. Execute the query, e.g. by clicking the "Execute" button. 4. Clear the query window, then type (everything between the double quotes): "Reconfigure" 5. Execute the query. 6. Then restart the SQL Server database, e.g. in SQL Server Configuration Manager or by simply restarting the service in the control panel. This solution is based on a forum entry by 'kabalweg' I found at an MSDN SQL Server Forum. And yes, it did work for me. And yes it works for both SQL Server 2005 and SQL Server 2005 Express.

C# Grammar

In case you are looking for a document that contains a C# grammar, then check out the ECMA-334 (PDF, 2.6 MBytes) specification. Starting with page 65 (or 87 of 553 if you use Adobe Reader) you'll find both the lexical and the syntactic grammar for C# 2.0, e.g. including generics, etc.

FormatException thrown by Convert.ChangeType Method

According to Microsoft's online documentation the method Convert.ChangeType(Object, Type) can throw the following two exceptions:

• InvalidCastException
• ArgumentNullException

Unfortunately, this list is not complete. When you try to convert the string "oops" to int32, this method throws a System.FormatException with the message "Input string was not in a correct format."

In this regard the online documentation for .NET 2.0 is incorrect. The behavior might be the same for .NET 3.0. I didn't verify the latter.

What's next for csUnit?

Now, that csUnit 2.1.2 has been released the question is certainly what is next for the tool. Here is my take. I think that one of the next items will be a simple first version of parameterized tests. We have looked at what other xUnit based testing frameworks offer, and there are a lot of very good ideas out there. The way csUnit will support it will certainly be inspired by what is already there. However, we also believe that in some cases the available implementations have shortcomings. Some unit testing frameworks don't offer parameterization at all. Others offer it, but are somewhat limited with regards to where the parameter values can come from. It would not surprise us if you had some thoughts on this as well. Please share them by posting on the "Open Discussion Forum" on SourceForge, or by sending an email to manfred at csunit dot org. Thanks!

csUnit 2.1.2 Released

Finally we have a new version of csUnit. It is version 2.1.2 and it's available at SourceForge. A lot of effort went into this release, and it is probably not an exaggeration to state that this is the best csUnit version ever. Here is what we did:

• Performance: Reduced overhead by approximately 50%
• Usability: Simplified setup, and also the user interface
• Features: Support for multiple categories, and we also added a Timeout parameter to the TestAttribute

It was very exciting to introduce new concepts to the design of the application, e.g. selectors. The code has improved in various ways, and it is amazing to see how more functionality can be provided with a seemingly similar sized codebase.

In particular I would like to thank Jake Anderson, Piers Lawson, and Markus Rentschler for their contributions and support. Also I'd like to thank our sponsors from Agile Utilities and JetBrains. And last but not least I'd like to thank all the users of csUnit who provided us with extremely valuable feedback, and also helped out with experiments to solve bugs. Thank you to all of you! It is a pleaseure to work with you!

Our next release is planned for June 2007. We have quite a few very good suggestions for additional exciting features, and we are looking forward to make them happen!

Codebase vs. Path Name - Different Casing on MS Platforms

While working on some code that loads assemblies I ran into an issue with Assembly.LoadFrom(pathName) in connection with the Assembly.CodeBase property. The method is supposed to load an assembly from the location given in the pathName parameter. When I pass as an example 'foo.dll' as a parameter, it loads the assembly and everything is fine. The interesting part starts, however, when I inspect the CodeBase property after the assembly has successfully loaded: Its value ends in "foo.DLL" (note the upper case file extension). This is certainly not a problem on a Microsoft platform, where file and folder names are case insensitive. If, however, you also intend to run your code on platforms where file names are case sensitive (e.g. Mono on Linux), then this behavior might be of interest to you as on those platforms "foo.DLL" and "foo.dll" are just two different files.

Performance, Overhead, and csUnit

Over the last several months we have been working on improving the performance of csUnit. Not that it was really bad. However, we thought that it is about time to look at whether we can improve it. Generally we improved two areas, one of which is of interest to users, while the second area is more of interest for the csUnit development team. Area one is basically the overhead that csUnit adds to the code that you execute. As a user you would like this to be as low as possible as you would like your resources (computer, but also your time) is mostly spent on what you really want to achieve. For improving the performance we are using JetBrains' dotTrace. It's an easy to use tool, and provided us with just the information we needed to reduce the overhead. For a recipe with about 4 assemblies containing tests you can expect an overhead of about 2 to 3 seconds on a decent notebook. Faster machines lead to better results. Currently we have a few options left, which we consider for future improvements, but right now we believe that we played the major cards. The second area was improving csUnit's own test suite. Again with the help of the profile, but also with csUnit's own "Statistics" tab, we identified the most expensive tests, and worked through them one at a time. We increased the use of mocks, but we also improved the testability of csUnit by introducing more internal interfaces. Overall we are now able to run the test suite with a speed of approx. 6,000 tests per minute on a decent notebook. We are currently shooting for a new version in March. We have a short list of known issues we want to fix. Stay tuned!

Mandatory Use Of Attributes in csUnit (Proposal)

We are considering to drop csUnit's support for finding Tests and TestFixtures based on naming conventions, e.g. fixture names end with Test and tests starting with Test. Instead I'd like to change the specification so that it becomes a requirement to use attributes, e.g. TestFixtureAttribute and TestAttribute, to mark fixtures and tests. The benefit would be a more consistent use of csUnit, e.g. TestAssemblyFixtureAttribute can be expressed with attributes only. The impact would be that all test fixtures and all tests that still rely on naming convention would have to augmented by assigning the TestFixtureAttribute to all fixtures and TestAttribute to all tests. Depending on the number of tests this might a substantial work. Send your feedback and comments to manfred at csunit dot org. Thank you!

What About csUnit 2.1?

Admittedly there wasn't much news around csUnit 2.1 for a while. But be assured that we are working on it, and we are hoping to make a release available in September 2006. Currently we are refactoring the code base, in particular we would like to make the "categories" feature much more powerful. A collateral will be an improved user interface for both the stand-alone application (csUnitRunner) and the Visual Studio 2005 add-in. Stay tuned!

Startup Tests in csUnit 2.0.4

The GUI runner of the new version csUnit 2.0.4 executes some startup tests. These checks certain aspects of the installation. The dialog box showing the execution of those startup tests will disappear automatically after about 3-4 seconds. The next maintenance release will execute these tests only once when the GUI has been started for the first time after installation. Currently it is run each time the GUI is started. Also, these tests are available from an option in the Help menu. Adding these startup tests is an experiment for improving the user experience of csUnit. All kind of feedback is highly welcome and appreciated. Please send email to manfred at csunit dot org. Thank you!

csUnit 2.0.4 Released

Another version of csUnit is available: csUnit 2.0.4. This is a maintenance release for csUnit 2.0.x, which is the version that has addins and wizards for VS2002 and VS2003. This release contains one bugfix for csUnitVSWizard (SourceForge Tracker ID 1528508: Can't find Wizard.config). Furthermore the setup has been modified so that csUnit assemblies, which need to be be COM visible, no longer register with a CodeBase key in the registry. If you need support for VS2005 you may try csUnit 2.1.x, which contains addins and wizards for VS2005 and also supports .NET 2.0.

csUnit 2.1.1 BETA released

Another beta release of csUnit 2.1 is available at csUnit's web site. Remember, version 2.1 is the first csUnit version that supports .NET 2.0 and Visual Studio 2005. For this beta version we focused on two major areas:

• Addin for Visual Studio
• Performance Engineering

The addin for Visual Studio is available again with a similar feature set as in previous versions. After adding a reference to csUnit to your project you will have two additional entries in your context menu for the project: On the performance side, we decided that we wanted to measure and reveal the amount of overhead csUnit adds to your unit tests. csUnit is the first unit testing tool, which provides that feature. We used dotTrace by JetBrains and Microsoft's CLRProfiler to improve overall performance. Our data shows that we have been able to reduce the overhead caused by csUnitRunner, the standalone GUI application to about 1 second per 100 tests. Compared to almost 10 seconds in the past, this is a significant improvement and saves valuable development time. Concurrently we have also started to talk to different tool vendors, some of them already providing support for csUnit. The idea is to make sure that csUnit provides for the best possible integration in order to help increasing your productivity.

csUnit 2.1.0 BETA Released

Finally a .NET 2.0 compatible version of csUnit is available. Although it doesn't have an addin for Visual Studio 2005 yet, it's still worthwhile to take a look. For instance: Did you ever wish you had a setup or teardown method for all your tests in one assembly? Then try this: [TestAssemblyFixture] public class TestData { [SetUp] public void CreateInMemoryDB() { //... } [TearDown] public void CleanupInMemoryDB() { //... } private InMemoryDB _database = null; } This is a just an example for illustration purposes. Don't send me a message asking for my code for the InMemoryDB class. I don't have it! As for csUnit 2.1.0 BETA, you can find it at http://www.csunit.org/download.

csUnit 2.0.1 released

Finally we got another release of csUnit finished (see version 2.0.1 on csUnit's web site). It took a while but there were many requests in do so. Although we don't have support for VS.NET 2005 yet, we plan to have that ready by end of March 2006. The new release offers a few enhancements, e.g. categories for tests and imcreased flexibility in the user interface for selecting which tests to run. Next we'll focus on:

• updating the collaterals for version 2.0.1
• then version 2.1, which will add support for VS.NET 2005

Determining Name And Path Of Output File in VS.NET 2005 Automation

When implementing an extension, e.g. an addin for VS, you may want to determine the path (location) and name of the assembly that is being built as part of a project. One way would be to read the project file, e.g. *.csproj. As it happens to be an XML file it is easy to determine the correct node. A different approach though is using the Project automation object. Project has a set of properties and for C#/VB.NET/J# projects it contains a property named "OutputFileName". The value of that property is the assembly name. Next, you need to determine the path. First you need to know the path to the project, which you can determine using the directory part of Project.FileName. This gives you the location of the project file. In order to determine the output path for the assembly, you need the active configuration for the project, which you obtain using Project.ConfigurationManager.ActiveConfiguration. The ActiveConfiguration object has a property named "OutputPath", which is the relative path from the project file to the output folder. One might be tempted to use ActiveConfiguration.OutputGroups. For that to work the project needs to have been built successfully once, which might not always be the case. Furthermore, Configuration.OutputGroups doesn't work in a handler for the solutions event Opened. Therefore I settled on the following code for determining the path and the name of the target assembly:

string GetOutputPathAndFile(Project p) {
   string outputPath;
   string outputFileName;
   string outputPathAndFile;
   string projectLocation;
   try {
      Configuration activeConf = p.ConfigurationManager.ActiveConfiguration;
      projectLocation = (new FileInfo(p.FileName)).DirectoryName;
      outputFileName = p.Properties.Item("OutputFileName").Value.ToString();
      outputPath = activeConf.Properties.Item("OutputPath").Value.ToString();
      outputPath = Path.Combine(projectLocation, outputPath);
      outputPathAndFile = Path.Combine(outputPath, outputFileName);
   }
   catch(Exception ex) {
      System.Diagnostics.Debug.WriteLine(ex.Message);
   }
   return outputPathAndFile;
}

If you are aware of a better solution, please don't hesitate to comment! I'm eager to learn.

Update: User Control in Tool Window of a Visual Studio Addin

After some more experimentation it seems that the last parameter of CreateToolWindow2() is null, if the hosted control is in a separate assembly / project. For instance: Suppose you have a solution containing two projects, let's call them MyAddIn and MyControls. The first one is your add-in itself and the second one contains some controls you want to have in a separate assembly as you want to use them also for other solutions, e.g. a stand-alone application. Now, if you have a UserControl in the project MyControls, let's call it MyUserControl1, then you can still host that control in your add-in. However, in this case the method CreateToolWindow2() returns null as the value of the last parameter. If on the other hand you add a UserControl, let's call it MyUserControl2, to the add-in project 'MyAddIn', and then host MyUserControl2 in the add-in, the last parameter of CreateToolWindow2() will contain a reference to your MyUserControl2 instance. Of course MyUserControl2 can in turn contain one or more instances of MyUserControl1. Strange that whether or not a UserControl is contained in the add-in assembly/project or not makes a difference regarding the last parameter of CreateToolWindow2(). Am I missing something?

The invoked member is not supported in a dynamic assembly - Reprise

Here is another workaround for the issue with the form designer: In some cases it is sufficient to just close and re-open the solution and/or Visual Studio. From my perspective this indicates a bug in the IDE. So it's back to Microsoft.