How to filter out rows with null values?

To filter out rows containing null values or spaces, use the ISNULL and IS_SPACES functions to test the value of the port. For example, if we want to filter out rows that contain NULLs in the FIRST_NAME port, use the following condition:

IIF(ISNULL(FIRST_NAME),FALSE,TRUE)

This condition states that if the FIRST_NAME port is NULL, the return value is FALSE and the row should be discarded. Otherwise, the row passes through to the next transformation.