Question

I have been trying to find the answer to this simple question – but so far couldn’t figure it out.

Let say I have MyDb.sqlproj, with various sql content (sprocs, views, trigger, etc).

I have added a new UDF through Add-> New item -> SQL CLR C#, User Defined Function.

For example:

namespace MyNameSpace
{
 public class MyClass
 {
    [SqlFunction(DataAccess = DataAccessKind.Read)]
    //I use different attributes here, but it doesn't matter
    public static int Method1()
    {
       return 0;
    }
 }
}

In MyDb.sqlproj Properties, SQLCLR tab MyDb is the name of assembly and default namespace

In my sql code I call the clr method using EXTERNAL NAME:

CREATE PROCEDURE ClrMethod1
  RETURNS [int] WITH EXECUTE AS CALLER
AS EXTERNAL NAME [MyDb].[MyNamespace.MyClass].[Method1]

I seem to tried everything to get the last line to compile. It cannot resolve the reference and get:

SQL71501: Function: [name of my sql function] has an unresolved
reference to Assembly [MyDb]

Please point me to the right way to get it working. What could I be missing?

I am using VS2010 SP1 and latest version of SSDT

Answer 1

You must add your compiled DLL containing your CLR code as a Reference. So under your MyDb SSDT project->References(right click)->Add Reference, browse to the DLL.

You could probably get away with referencing the project instead of the DLL if you had the CLR(class library) project in the same solution, but in my case I am referencing a DLL(compiled for a seperate solution).

As far as the format of the AS EXTERNAL NAME line:

AS EXTERNAL NAME [AssemblyName].[ClassName].[FunctionName]

Note: For CLR objects I remove the namespaces from around my classes/code just to simplify things, because this step is usually the most problematic. It is easy to confuse the AssmeblyName/DLL Name/Namespace. The AssemblyName is found in your CLR class library project by accessing the Project Properties->Application->”Assembly Name:”. I would remove any non alpha-numeric/spaces from it just to simplify the name and rule out that as a problem.

So I would try that, and once you get that working, if you really want namespaces, then you can add the namespace and figure out the syntax from there, and at least you know the other parts are correct.

---

Ok reallized that you have a *.cs file actually inside the same SSDT project. so in that case if your code is this:

CS file:

public partial class UserDefinedFunctions
{
    [Microsoft.SqlServer.Server.SqlFunction]
    public static SqlString SqlFunction1()
    {
        // Put your code here
        return new SqlString (string.Empty);
    }
}

SQL file:

CREATE PROCEDURE ClrMethod1
  RETURNS [int] WITH EXECUTE AS CALLER
AS EXTERNAL NAME [MyDB].[UserDefinedFunctions].[SqlFunction1]

This compiles for me. Note: Again no namespace was used. When I did Add New Item… the generated code did not come with a namespace.