Programming: Assembly (Definitions)

"An assembly is the unit of deployment and versioning in the .NET Framework. An assembly contains a manifest, metadata, MSIL, and possibly binary resources. Most assemblies are single files, but an assembly can consist of multiple files, such as DLLs, picture files, and even HTML files." (Adam Nathan, ".NET and COM: The Complete Interoperability Guide", 2002)

"The unit of deployment and versioning in the .NET Framework. It establishes the namespace for resolving requests for types and determines which types and resources are exposed externally and which are accessible only from within the assembly. An assembly includes an assembly manifest that describes the assembly's contents." (Damien Watkins et al, "Programming in the .NET Environment", 2002)

"A managed application module that contains class metadata and managed code as an object in SQL Server. By referencing an assembly, CLR functions, CLR stored procedures, CLR triggers, user-defined aggregates, and user-defined types can be created in SQL Server." (Thomas Moore, "MCTS 70-431: Implementing and Maintaining Microsoft SQL Server 2005", 2006)

"A managed application module, composed of class metadata and managed code, that can be embedded in a database solution as a database object in SQL Server 2005." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"Application logic that is stored in, and managed by, the SQL Server database server, including objects like triggers, CLR software, and stored procedures. Assemblies are written in a .NET language, such a C# or Visual Basic." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"In SQL Server, a .NET assembly is a compiled SQL CLR executable or DLL." (Michael Coles, "Pro T-SQL 2008 Programmer's Guide", 2008)

"A managed application module that contains class metadata and managed code." (Jim Joseph et al, "Microsoft® SQL Server™ 2008 Reporting Services Unleashed", 2009)

"In .NET applications, the smallest self-contained unit of compiled code. An assembly can be a complete application, or a library that can be called by other applications." (Rod Stephens, "Start Here!™ Fundamentals of Microsoft® .NET Programming", 2011)

"The smallest independent unit of compiled code. Typically, this is a Dynamic Link Library (DLL) or executable program." (Rod Stephens, "Stephens' Visual Basic® Programming 24-Hour Trainer", 2011)

"A managed application module containing class metadata and managed code as an object in SQL Server, against which CLR functions, stored procedures, triggers, user-defined aggregates, and user-defined types can be created in SQL Server." (Microsoft, "SQL Server 2012 Glossary", 2012)

"In SQL Server, a .NET assembly is a compiled SQL CLR executable or DLL." (Jay Natarajan et al, "Pro T-SQL 2012 Programmer's Guide" 3rd Ed., 2012)

"The fundamental logical unit of managed code, consisting of one or more files containing Common Intermediate Language instructions and metadata. See also CIL." (Mark Rhodes-Ousley, "Information Security: The Complete Reference" 2nd Ed., 2013)

💠🛠️SQL Server: Administration [Could not load file or assembly Microsoft.MSXML]

I’m not programming anymore as I used to do, though from time to time I still fancy some .Net programming. It’s not much, small applications or CLR-based libraries for SQL Server. Quite often, when I return to programming after a long pause it happens that I run into problems, finding that something that was working previously stopped working. During my last attempt I couldn’t load anymore one of the projects I worked on, receiving the following error:

“Could not load file or assembly ‘Microsoft.MSXML, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ or one of its dependencies. The system cannot find the file specified.”

Same happened when I tried to load other projects. I looked then into GAC in “C:\Windows\assembly” folder and saw no reference to Microsoft.MSXML dll. So I tried to install the msxml6.dll assembly in GAC however, never doing that, I run into another problem. In the meantime I tried to install the Visual Studio 2010 SP1, the MSXML 6.0 and even the Windows .Net SDK. All this without success. After several good hours, I returned to one of the forum posts (here) I run into in a first place. Thomas Sun was pointing that it might be a problem with the Microsoft Document Explorer 20xx. The solution was to reinstall it from  “C:\Program Files\Common Files\microsoft shared\Help 9\Microsoft Document Explorer 2008”. Once I did that everything was back to normal. At least until I’ll run into another issue.

After all this there is still one positive point: I managed to install SP1 and all the goodies it comes with, and I’m thinking here at the support for HMTL5. The downside – several good hours of lost time! I don’t want to think how much time I lost until now trying to solve things that were supposed to work in a first place – probably weeks, months…  That’s part of programmers’ life.

Disclaimer:
As Microsoft changed the whole structure of their support websites, most of the resources become unavailable. Therefore I had to remove the links pointing to the various sources.

💎SQL Reloaded: Porting 32 bit CLR UDFs on 64 bit Platforms

Today I tried to port on a 64 bit platform a few of the CLR UDFs created in the previous posts, this time being constrained to use Visual Basic Studio 2010 Express to create and build the assembly on a x86 platform, and install the assembly on a x64 SQL Server box. From the previous troubleshooting experience between the two platforms, I knew that there will be some challenges, fortunately there was nothing complex. Under SSIS 2008 it’s possible to choose the targeted platform, therefore I was expecting to have something similar also in VB Studio 2010 Express, and after a simple review of Project Properties, especially in what concerns the Compile settings, I found nothing relevant. I tried then the standard approach, so I built the solution, copied the .dll on the target server and tried to register the assembly though I got the following error:

Msg 6218: %s ASSEMBLY for assembly '%.*ls' failed because assembly '%.*ls' failed verification. Check if the referenced assemblies are up-to-date and trusted (for external_access or unsafe) to execute in the database. CLR Verifier error messages if any will follow this message%.*ls

After several attempts to google for a solution on how to port 32 bit CLR UDFs on 64 bit Platform or on how to configure VB Studio 2010 Express in order to target solutions for 64 bit platforms, I found a similar question (VB Express target x86 Platform) in MSDN,  Johan Stenberg’s answer completed by JohnWein’s hint, led me to the “Issues When Using Microsoft Visual Studio 2005” document, to be more specific to 1.44 section "References to 32-bit COM components may not work in VB and C# Applications running on 64-bit platforms", of importance being the part talking about "Express Editions". In the document is specified how to modify the project and add in the first PropertyGroup section a PlatformTarget tag with the text value x86, therefore what I had to do was to add the respective tag but with the value x64. After doing this change everything worked smoothly. It’s kind of a mystery why Microsoft hasn’t enabled this feature in Express versions, but in the end I can live with it as long there is a workaround for it.

Happy coding!