Error mysql syntax trigger - mysql

Question

According phpmyadmin, I have a syntax error in this trigger :
CREATE TRIGGER insert_device
AFTER INSERT ON table_e
FOR EACH ROW
BEGIN
DECLARE m_id_a INTEGER;
DECLARE m_id_d INTEGER;
m_id_d := 0;
SELECT id_a INTO m_id_a FROM table_ua WHERE ua_eui = NEW.eui LIMIT 1;
SELECT id_d INTO m_id_d FROM table_d WHERE d_idapp = m_id_a ORDER BY id asc LIMIT 1;
IF (m_id_d == 0) THEN
INSERT INTO table_d (d_addr, d_eui, d_apps, d_nwks, d_idapp)
VALUE (NEW.addr, NEW.eui, NEW.apps, NEW.nwks, m_id_a);
ELSE
UPDATE TABLE table_d
SET
d_addr = NEW.addr,
d_eui = NEW.eui,
d_apps = NEW.apps,
d_nwks = NEW.nwks
WHERE id_d = m_id_d;
END IF;
END
The error is :
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ':= 0;
What is the error ? I don't understand what I am doing wrong..
Thanks.

Answer 1

There are several syntax errors in your trigger:
declare a variable, you should invoke it with set;
IF expression can not use ==, just one equal is ok;
update syntax only need to specify table name like UPDATE table_d SET ....
So please try following trigger:
delimiter $$
CREATE TRIGGER insert_device
AFTER INSERT ON table_e
FOR EACH ROW
BEGIN
DECLARE m_id_a INTEGER;
DECLARE m_id_d INTEGER;
set m_id_d = 0;
SELECT id_a INTO m_id_a FROM table_ua WHERE ua_eui = NEW.eui LIMIT 1;
SELECT id_d INTO m_id_d FROM table_d WHERE d_idapp = m_id_a ORDER BY id asc LIMIT 1;
IF (m_id_d = 0) THEN
INSERT INTO table_d (d_addr, d_eui, d_apps, d_nwks, d_idapp)
VALUE (NEW.addr, NEW.eui, NEW.apps, NEW.nwks, m_id_a);
ELSE
UPDATE table_d
SET
d_addr = NEW.addr,
d_eui = NEW.eui,
d_apps = NEW.apps,
d_nwks = NEW.nwks
WHERE id_d = m_id_d;
END IF;
END
$$