How to update DB2 table with a join?

Question

I have two tables and I want to update by joining them. I am using DB2 V9.7.

ORDER_APPROVALS

ORDER_ID    CREATED_BY_ID   CREATED_BY         


        

Answer 1

You are looking for the MERGE statement:

merge into ORDER_ATTRIBUTE ot
    using (select ORDER_ID, CREATED_BY_NAME
             from ORDER_APPROVALS
            where PROCESS_DT is null) oa
    on
       (ot.ORDER_ID = oa.ORDER_ID)
    when matched 
     and ot.ATTRIBUTE_ID = 123
    then update set VALUE = oa.CREATED_BY_NAME;