UPDATE (SELECT ... FROM t1,t2 WHERE ... ) SET ...;

DROP TABLE t1;

DROP TABLE t2;

CREATE TABLE t1 (id INT PRIMARY KEY, p1 INT);

INSERT INTO t1 VALUES (1, 100);

INSERT INTO t1 VALUES (2, 100);

CREATE TABLE t2 (id INT, p2 INT);

INSERT INTO t2 VALUES (1, 10);

INSERT INTO t2 VALUES (1, 20);

UPDATE (SELECT p1,p2 FROM t1,t2 WHERE t1.id=t2.id AND p1=100) SET p2=p2+1;

SELECT * FROM t2;

	ID	   P2

---------- ----------

	 1	   11

	 1	   21

UPDATE (SELECT p1,p2 FROM t1,t2 WHERE t1.id=t2.id AND p1=100) SET p1=p1+1;

UPDATE (SELECT p1,p2 FROM t1,t2 WHERE t1.id=t2.id AND p1=100) SET p1=p1+1

                                                                  *

ERROR at line 1:

ORA-01779: cannot modify a column which maps to a non key-preserved table