Question

I have a database that is supposed to store data in any language, there is going to be a column that tells me which locale it is, so i can’t rely on database collation and will have to specify collation at runtime in queries.

I also have the problem that i want to use EF for dataaccess, as we know using EF one cannot specify collation at runtime. I am thinking about creating a sql function that takes collation as argument and apply that function in all of the Linq Queries.

but this fails

CREATE FUNCTION fn_Compare
(   
    @TextValue nvarchar(max),
    @Culture varchar(10)
)
RETURNS  nvarchar(max)
AS
BEGIN
    RETURN @TextValue COLLATE @Culture
END
GO

does anyone know if this can be done ?

Answer 1

You cannot do this. The collation returned by the function needs to be consistent across all the return values. For instance, the following generates an error:

create function testfn (@test varchar(100), @i int)
returns varchar(100)
as
begin
    return(case when @i = 0 then @test collate SQL_Latin1_General_CP1_CS_AS
              else @test collate SQL_Latin1_General_CP1_CI_AS
         end)
end;

The error is due to a collation conflict.

What you can do is use:

alter database collate <whatever>

Or, alternatively, create a new working database with the collation you want.