Join on multiple columns only if column is not null

Hi ryan_mayu , it is the same as raw data.  The expected output is to see 2 rows if I do select * from TABLEA and select Description from DESC where

TABLEA Carrier = DESC Carrier (only if Carrier its not null) and

TABLEA Group = DESC Group (only if Group is not null) and

TABLEA Mode = DESC Mode (only if Mode is not null) and
TABLEA State = DESC State (only if State is not null)

so these are the only 2 records I want to see:

Verizon A Ship NY 10 abcde  (since Ship and NY in DESC matches Ship and NY in TABLEA)

ATT B Air CA 20 efghi  (since all columns match both tables)

Thanks!