SQLCLR custom aggregate with multiple sql_variant parameters

Question

Hy,

I have post a question about CLR User-Defined Aggregates few month ago oon this post.

This works like a charm. But now I would like to quite the same functi

Answer 1

When using SQL_VARIANT / object, you can determine the type by using the GetType() method as follows:

[Microsoft.SqlServer.Server.SqlFunction(IsDeterministic = false, IsPrecise = true)]
public static SqlBoolean GetIfSmallInt(object SomeValue)
{
    return (SomeValue.GetType() == typeof(SqlInt16));
}

And test it using:

DECLARE @DateTime DATETIME = GETDATE();
SELECT dbo.GetIfSmallInt(@DateTime);
-- 0

DECLARE @SmallInt SMALLINT = 5;
SELECT dbo.GetIfSmallInt(@SmallInt);
-- 1

Please keep in mind that using SQL_VARIANT / object has a noticeable performance penalty. Only use it when you absolutely need to. If you just need to pass in INT / SMALLINT / BIGINT, then use BIGINT / SqlInt64 as the input parameter type.