MYSQL Trigger not working

MySQLtrigger

I am trying to create the following trigger:

CREATE TRIGGER update_customers AFTER INSERT ON wp_usermeta
    FOR EACH ROW 
    BEGIN
            if new.wp_metakey = first_name then insert into test_customer(first_name) values (new.wp_meta_value);
    END

I keep getting a 1064 error that says, "You have an error in your SQL syntax; check the manual that corresopons to your MySQL server version for the right syntaxt to use near " at line 5"

What am I doing wrong?

Best Answer

The first problem is that you don't have an END IF;.

The next problem (assuming that you aren't doing this and just didn't include it in the question) is that when you have a compound statement, you have to change the statement delimiter from ; to something else so that the client will send the entire CREATE TRIGGER statement to the server as a single statement.

Finally, the column "first_name" probably needs to be qualified with NEW (assume you're referencing a column in wp_usermeta called "first_name".

DELIMITER $$
DROP TRIGGER IF EXISTS update_customers $$
CREATE TRIGGER update_customers AFTER INSERT ON wp_usermeta
FOR EACH ROW 
BEGIN
  IF NEW.wp_metakey = NEW.first_name THEN 
    INSERT INTO test_customer(first_name) values (NEW.wp_meta_value);
  END IF;
END $$
DELIMITER ;

Related Solutions

MySQL Join – Troubleshooting Full Outer Join Not Working

So far as I know, you can't do a full outer join in MySQL, so just run it as the UNION of a LEFT JOIN and a RIGHT JOIN as

SELECT * FROM 
cajas LEFT JOIN almacenes ON almacenes.codigo = cajas.almacen
UNION
SELECT * FROM 
cajas RIGHT JOIN almacenes ON almacenes.codigo = cajas.almacen;

I think this would fix your problem.

EDIT: After a quick Googling, I realized that the above may not be perfect for all cases. Instead you could do

SELECT * FROM 
cajas LEFT JOIN almacenes ON almacenes.codigo = cajas.almacen
UNION ALL
SELECT * FROM 
cajas RIGHT JOIN almacenes ON almacenes.codigo = cajas.almacen
WHERE cajas.almacen IS NULL;

See this blog post for reference.

MySQL Trigger – How to Create Trigger for Update or Insert in Another Table

First, you need to specified when do you want to run the trigger inside the table. I've edited your trigger and use AFTER UPDATE and AFTER INSERT:

AFTER INSERT:

USE `TEST`;
DELIMITER $$
DROP TRIGGER IF EXISTS MEDICAMENTO.monthUpdateTriggerAI$$
USE `TEST`$$
    CREATE DEFINER = CURRENT_USER TRIGGER `TEST`.`monthUpdateTriggerAI` AFTER INSERT ON `TestTable` FOR EACH ROW
    BEGIN
    SET @COUNT=(SELECT COUNT(*) FROM TestTable2 WHERE (ItemId=NEW.ItemId AND Year=YEAR(NEW.Date) AND Month=MONTH(NEW.Date)));
    IF @COUNT=0 THEN
        INSERT INTO TestTable2 (ItemId,Year,Month,Open,Close,Increase ) VALUES 
        (NEW.ItemId , YEAR(NEW.Date), MONTH(NEW.Date),NEW.Value,NEW.Close,0.0); 
    ELSE
        UPDATE TestTable2 SET TestTable2.Close=NEW.Close AND Increase=(NEW.Close/(SELECT 
        Open FROM TestTable WHERE (Year=YEAR(NEW.Date) and Month=MONTH(NEW.Date)) LIMIT 1))
        WHERE (Year=YEAR(NEW.Date) and Month=MONTH(NEW.Date));
    END IF;
    END;
$$
DELIMITER ;

AFTER UPDATE:

USE `TEST`;
DELIMITER $$
DROP TRIGGER IF EXISTS MEDICAMENTO.monthUpdateTriggerAU$$
USE `TEST`$$
    CREATE DEFINER = CURRENT_USER TRIGGER `TEST`.`monthUpdateTriggerAU` AFTER UPDATE ON `TestTable` FOR EACH ROW
BEGIN

    UPDATE TestTable2 SET TestTable2.Close=NEW.Close AND Increase=(NEW.Close/(SELECT 
    Open FROM TestTable WHERE (Year=YEAR(NEW.Date) and Month=MONTH(NEW.Date)) LIMIT 1))
    WHERE (Year=YEAR(NEW.Date) and Month=MONTH(NEW.Date));

END;
$$
DELIMITER ;

Note: Be careful about the SELECT Open FROM TestTable WHERE (Year=YEAR(NEW.Date) and Month=MONTH(NEW.Date)), I've added a LIMIT 1 to avoid duplicate rows.

Change the database TEST.

You can also use ON DUPLICATE KEY on the two triggers execution.

You can get more information in the MySQL's documentation manual.