Обсуждение: after update trigger ?
Can an after update trigger function do an insert into the the same table ? Thanks Tom -- View this message in context: http://postgresql.1045698.n5.nabble.com/after-update-trigger-tp4333008p4333008.html Sent from the PostgreSQL - novice mailing list archive at Nabble.com.
Sorry, one of those can't see the forest from the trees things .... Tom -- View this message in context: http://postgresql.1045698.n5.nabble.com/after-update-trigger-tp4333008p4333066.html Sent from the PostgreSQL - novice mailing list archive at Nabble.com.
On Fri, Apr 22, 2011 at 7:23 PM, tmoore <tmoore@ttitech.net> wrote:
postgres=# SELECT * FROM NEW_EMP;
eno | ename | sal
-----+--------+-------
1 | xx | 9000
2 | ABC | 90000
(2 rows)
2. Create a function
CREATE OR REPLACE FUNCTION RAGHU() RETURNS TRIGGER
AS
$$
BEGIN
INSERT INTO NEW_EMP VALUES(1,'RAGHU',90000);
RETURN NEW;
END;
$$
LANGUAGE PLPGSQL;
3. Create a trigger
CREATE TRIGGER RAGHU_TRI AFTER UPDATE ON NEW_EMP FOR EACH ROW
4. Update the records in "NEW_EMP" table
Can an after update trigger function do an insert into the the same table ?
Yes, we can do and code snippet as follows::
1. Fetch records from Existing Table
eno | ename | sal
-----+--------+-------
1 | xx | 9000
2 | ABC | 90000
(2 rows)
2. Create a function
CREATE OR REPLACE FUNCTION RAGHU() RETURNS TRIGGER
AS
$$
BEGIN
INSERT INTO NEW_EMP VALUES(1,'RAGHU',90000);
RETURN NEW;
END;
$$
LANGUAGE PLPGSQL;
3. Create a trigger
CREATE TRIGGER RAGHU_TRI AFTER UPDATE ON NEW_EMP FOR EACH ROW
EXECUTE PROCEDURE RAGHU();
postgres=# UPDATE NEW_EMP SET ENAME='RAJESH' WHERE ENO=2;
UPDATE 1
5. Fetch Records from "NEW_EMP" Table
postgres=# SELECT * FROM NEW_EMP;
eno | ename | sal
-----+--------+-------
1 | XX | 9000
2 | RAJESH | 90000
1 | RAGHU | 90000
Thanks & Regards
Raghu Ram
EnterpriseDB Corporation
The Enterprise PostgreSQL Company
Raghu Ram
EnterpriseDB Corporation
The Enterprise PostgreSQL Company
Thanks
Tom
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tmoore <tmoore@ttitech.net> writes:
> Can an after update trigger function do an insert into the the same table ?
Sure. You have to avoid recursively triggering the same trigger, but an
insert wouldn't trigger the update trigger.
regards, tom lane