What if there will be a NULL values? How do you change the expression to handle NULL?
(DT_DATE)(SUBSTRING([BirthDate], 1, 4) + "-" + SUBSTRING([BirthDate], 5, 2)+ "-" + SUBSTRING([BirthDate], 7, 2))
I tried this one but not working. (ISNULL(availability_start) ? (DT_DBTIMESTAMP)NULL :(DT_DATE)(SUBSTRING([BirthDate], 1, 4) + "-" + SUBSTRING([BirthDate], 5, 2)+ "-" + SUBSTRING([BirthDate], 7, 2))