Question

I have two tables with the same ID column PK/FK. I need to update them with data from a third table.

IF EXISTS (SELECT * C, B WHERE B2 = C4 AND C6 = NULL)
Update A
   Set A2=C2,
       A3=C3,
       B2=C4,
       B3=C5
 From C
 Where C6 = NULL

How do I put the join in to link the proper B row to the A row? I can elminiate the last where statement as it is limited by that criteria already, correct?

Answer 1

You cannot update two tables at once, you can simply wrap two update statements in a TRANSACTION.:

BEGIN TRANSACTION
--perform a update...
    UPDATE A
    SET 
      A.A2=C.C2,
      A.A3=C.C3
    FROM
    MyTableA A
    INNER JOIN MyTableC C
    ON C.ID = A.ID...
--perform b update
   UPDATE B...
COMMIT