3 ° dll partito in SQL Server CLR

Question

Ho bisogno di utilizzare una terza parte DLL in un trigger codice C # in SQL Server CLR

Ma quando provo ad aggiungere il riferimento mostra solo alcune DLL da SQL Server.

Come posso aggiungere il mio terze parti dll per SQL Server?

Answer 1

You can only add references to those assemblies which have been registered with Sql Server. If they are not registered, they will no show up in the Add References dialog.

There are a number of steps you'll need to do register a DLL, firstly you'll need to reconfigure your database:

ALTER DATABASE [MyDatabase] SET TRUSTWORTHY ON;
sp_configure 'clr enabled', 1;
RECONFIGURE;

Once this is done, Sql Server is CLR enabled. Next, you'll need to register your assembly:

CREATE ASSEMBLY [MyAssembly] AUTHORIZATION [MyUser]
FROM 'C:\CLR\MyAssembly.dll'
WITH PERMISSION_SET = SAFE

If this last script runs correctly, the assembly is now registered, and will appear in the Add References dialog.

What you will need to consider though, is the application security of your Sql Server CLR configuration:

1. Prefer to register an assembly as SAFE, only in exceptional circumstances should you use EXTERNAL_ACCESS or UNSAFE.
2. Don't expect to be able to do everything you can on Full-trust CLR (i.e., not the CLR hosted by Sql Server) - the SQLCLR is a sandboxed runtime.
3. Don't try and load assemblies dynamically, as Assembly.Load() is purposefully restricted.
4. You may need to ensure the 3rd party library is signed with a public key if you plan on using UNSAFE.
5. Code executing runs in the context of the identity of the service running Sql Server (I think!)
6. Database access made from a hosted assembly (e.g. via context connection = true;) runs in the context of the connected user, so you need to make sure you are aware what access that library has to your data.

Answer 2

I am assuming you are asking about alternatives to installing SQL CLR assemblies from Visual Studio.

Having the code in Visual Studio is not required.

Deploying CLR Database Objects on MSDN details the options, including SQL statements and deployment scripts.

Answer 3

I use a very large 3rd party DLL that takes a web page and converts it into a PDF.

The PDF is saved on a file share and the database is updated as to it's location and type.

This is a 3-step process:

1. Create a console app that uses the 3rd party DLL to create the PDF and accept the URL and FilePath as parameters and returns the PDF size and number of pages.

2. Create a CLR stored procedure that then calls the console app on the server

3. I wrap this all into a single stored procedure that calls the CLR app to create the PDF and then I write meta-data about it to the database.

I realize this is not perfect and by no means should you do anything so crazy inside a trigger!

I only mention it here for others with questions about using 3rd Party DLL's in their CLR.

My hope is that by spinning off a cmd.exe console to run the 3rd Party DLL, instead of running everything in-proc, if it crashes, it won't adversely affect SQL Server as much. That's what I hope.

Please comment if this is a really-bad approach and why.