oracle触发器（当插入或删除或修改一张表A时，能把新数据同步到另一张结构相同的表B里面）

oracle触发器（当插入或删除或修改一张表A时，能把新数据同步到另一张结构相同的表B里面）

create or replace trigger testT

AFTER INSERT OR UPDATE OR DELETE ON A

for each row

declare

-- local variables here

begin

IF INSERTING THEN

INSERT INTO b(a,b) VALUES(:NEW.a,:NEW.b);

ELSIF DELETING THEN

DELETE FROM b WHERE a=:OLD.a;

ELSE

UPDATE b SET b=:NEW.b WHERE a=:OLD.a;

END IF;

end testT;

SQL> desc a

Name Type Nullable Default Comments

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

A VARCHAR2(20) Y

B VARCHAR2(20) Y

SQL> desc b;

Name Type Nullable Default Comments

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

A VARCHAR2(20) Y

B VARCHAR2(20) Y

SQL> insert into a values('a','b');

1 row inserted

SQL> commit;

Commit complete

SQL> select * from b;

A B

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

a b

SQL> update a set b='c' where a='a';

1 row updated

SQL> commit;

Commit complete

SQL> select * from b;

A B

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

a c

SQL> delete from a where a='a';

1 row deleted

SQL> commit;

Commit complete

SQL> select * from b;

A B

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

SQL>