Question

Assume the assembly dll:

using Microsoft.SqlServer.Server;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System;
using System.Text;

namespace CLRFunctions
{
    public class T
    {
        [SqlFunction(DataAccess = DataAccessKind.Read)]
        public static String NormalizeString(String s, String normalizationForm)
        {
            NormalizationForm form = NormalizationForm.FormC;

            if (String.Equals(f, "FormD", StringComparison.OrdinalIgnoreCase))
                form = NormalizationForm.FormD;

            return s.Normalize(form);
        }
    }
}

Note: Target the assembly to .NET 3.5 as SQL Server doesn’t support .NET 4.0

Copy the assembly to a location, and "creating" the assembly works fine:

CREATE ASSEMBLY CLRFunctions FROM 'c:\Program Files\My App\CLRFunctions.dll';

Note: And then enable CLR functions, otherwise they are broken by default:

sp_configure 'show advanced options', 1;
GO
RECONFIGURE;
GO
sp_configure 'clr enabled', 1;
GO
RECONFIGURE;
GO

Created the user-defined function fails:

CREATE FUNCTION NormalizeString(@s nvarchar(max), @normalizationForm varchar(50)) 
RETURNS nvarchar(max)
AS EXTERNAL NAME CLRFunctions.T.NormalizeString

fails with error:

Msg 6505, Level 16, State 2, Procedure NormalizeString, Line 1
Could not find Type 'T' in assembly 'CLRFunctions'.

Why can SQL Server not find type T in assembly CLRFunctions?

Note: Why T? Cause Microsoft did.

Answer 1

Try

CREATE FUNCTION NormalizeString(@s nvarchar(max), 
                                @normalizationForm nvarchar(50)) 
RETURNS nvarchar(max)
AS EXTERNAL NAME CLRFunctions.[CLRFunctions.T].NormalizeString