Trigger (AFTER/BEFORE) In Mysql - mysql

Question

I have a trigger which is working fine.
CREATE TRIGGER crm_listings__au
AFTER UPDATE
ON crm_listings FOR EACH ROW
INSERT INTO crm_listings_versions
SELECT
'update', NULL, NOW(), NULL, d.*
FROM
crm_listings AS d
WHERE
d.id = NEW.id;
Now I want to keep track of the field column name also. I am thinking I could not do in above query so I changed to below trigger
CREATE TRIGGER crm_listings__au
BEFORE UPDATE
ON crm_listings
FOR EACH ROW
BEGIN
IF OLD.type != NEW.type
THEN
INSERT INTO crm_listings_versions
SELECT
'update', NULL, NOW(), 'type', d.*
FROM
crm_listings AS d
WHERE
d.id = NEW.id;
END IF;
IF OLD.price != NEW.price
THEN
INSERT INTO crm_listings_versions
SELECT
'update', NULL, NOW(), 'price', d.*
FROM
crm_listings AS d
WHERE
d.id = NEW.id;
END IF;
END;
$$
When I run this code, I get this error:
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 '' at line 10
UPDATE:
I followed this post on stackoverflow

Answer 1

#kordirko: Can you please explain a little bit?
Please study the documentation: http://dev.mysql.com/doc/refman/5.7/en/stored-programs-defining.html
If you use the mysql client program to define a stored program
containing semicolon characters, a problem arises. By default, mysql
itself recognizes the semicolon as a statement delimiter, so you must
redefine the delimiter temporarily to cause mysql to pass the entire
stored program definition to the server.
To redefine the mysql delimiter, use the delimiter command. The
following example shows how to do this for the dorepeat() procedure
just shown. The delimiter is changed to // to enable the entire
definition to be passed to the server as a single statement, and then
restored to ; before invoking the procedure. This enables the ;
delimiter used in the procedure body to be passed through to the
server rather than being interpreted by mysql itself.
Simple example - I am using MySql Workbench and have copied and pasted your trigger. First some dummy tables:
create table crm_listings(
id int,
type int,
price int
);
create table crm_listings_versions(
ttype varchar(100),
something varchar(100),
d date,
something1 varchar(100),
id int,
type int,
price int
);
And now I run your code without DELIMITER
CREATE TRIGGER crm_listings__au BEFORE UPDATE ON crm_listings
FOR EACH ROW
BEGIN
IF OLD.type != NEW.type
THEN
INSERT INTO crm_listings_versions SELECT 'update', NULL, NOW(), 'type', d.* FROM crm_listings AS d WHERE d.id = NEW.id;
END IF;
IF OLD.price != NEW.price
THEN
INSERT INTO crm_listings_versions SELECT 'update', NULL, NOW(), 'price', d.* FROM crm_listings AS d WHERE d.id = NEW.id;
END IF;
END;
$$
Error Code: 1064. You have an error in your SQL syntax; check the manual
that corresponds to your MySQL server version
for the right syntax to use near '' at line 10 0.000 sec
Outcome = Error
Then the same, but with the DELIMITER command:
DELIMITER $$
CREATE TRIGGER crm_listings__au BEFORE UPDATE ON crm_listings
FOR EACH ROW
BEGIN
IF OLD.type != NEW.type
THEN
INSERT INTO crm_listings_versions SELECT 'update', NULL, NOW(), 'type', d.* FROM crm_listings AS d WHERE d.id = NEW.id;
END IF;
IF OLD.price != NEW.price
THEN
INSERT INTO crm_listings_versions SELECT 'update', NULL, NOW(), 'price', d.* FROM crm_listings AS d WHERE d.id = NEW.id;
END IF;
END;
$$
DELIMITER ;
0 row(s) affected
Outcome = Success