Question : SSIS - Dynamic Derived Column?

I can use a Derived Column transformation to add a column to my data set (Please see the attached image file). Currently, the value of the testColumn is always 5. But I want to be able to populate this value dynamically from the database using a select statement. For instance, I tried to replace "5" in the "Expression" column with the following statement:

select testColumn from
where

Of course, the editor would not accept my entry. Is there any other way to add a column to an already existing dataset - in SSIS package - whose value populates from the sql database dynamically?

Answer : SSIS - Dynamic Derived Column?

Instead of doing it through a derived column...why don't you just do it using an additional subquery at the source?