Update with self-join

Oracle does not support JOIN clause in UPDATE statements.

Use this:

MERGEINTO    contactassociations ca1USING   contactassociations ca2ON      (        ca1.contactid = ca2.contactid        AND ca1.entitytable = 'EMPLOYER'        AND  ca2.entitytable = 'CLIENT'        )WHEN MATCHED THENUPDATESET     parentid = ca2.id

I find the following style simpler to read, but you need to use an alias after the UPDATE key word, not the table name:

UPDATE ca1SET    ca1.parentid = ca2.idFROM contactassociations ca1LEFT JOIN contactassociations ca2 ON (ca1.contactid = ca2.contactid)WHERE ca1.entitytable = 'EMPLOYER' AND ca2.entitytable = 'CLIENT'

-- Method #1update emp set MANAGERNAME= mgr.EMPNAMEFROM SelfJoinTable emp , SelfJoinTable mgr where emp.MANAGERID = mgr.EMPID-- Method #2update emp set  MANAGERNAME= mgr.EMPNAME  FROM SelfJoinTable emp    LEFT OUTER JOIN SelfJoinTable mgr    ON emp.MANAGERID = mgr.EMPID-- Method #3update emp set  MANAGERNAME= mgr.EMPNAME  FROM SelfJoinTable emp    JOIN SelfJoinTable mgr    ON emp.MANAGERID = mgr.EMPID-- Method #4update emp set  MANAGERNAME= mgr.EMPNAME  FROM SelfJoinTable emp    inner JOIN SelfJoinTable mgr    ON emp.MANAGERID = mgr.EMPID