String.IsNullOrEmpty like function for VARCHARs in SQL?

Question

Say I\'ve got a function or stored procedure that takes in several VARCHAR parameters. I\'ve gotten tired of writing SQL like this to test if these parameters have a value:

Answer 1

You can do ISNULL(@SomeVarcharParam, '') <> '' or you can create a UDF that returns a bit:

create function dbo.IsNullOrEmpty(@x varchar(max)) returns bit as
BEGIN
IF @SomeVarcharParm IS NOT NULL AND LEN(@SomeVarcharParm) > 0
    RETURN 0
ELSE
    RETURN 1
END

And call that using IF NOT dbo.IsNullOrEmpty(@SomeVarcharParam) BEGIN ...

Keep in mind that when calling a UDF, you MUST prefix the owner of it (here, dbo.)