T-SQL: How to use parameters in dynamic SQL?

Question

I have the following dynamic query which is working fine without the WHERE clause, which is expecting UNIQUEIDENTIFIER.

When I pass it in,

Answer 1

DECLARE @ParmDefinition NVARCHAR(500)
SET @ParmDefinition = '@p_CreatedBy UNIQUEIDENTIFIER'

EXEC sp_executesql @sql, @ParmDefinition, @p_CreatedBy = @p_CreatedBy