syntax error in create trigger, what's wrong?

问题:

can somebody tell me what is wrong with the syntax of my code please? (this is the exact and only code I'm highlighting and running so line numbers should match up)

CREATE TRIGGER `trg_part_upd` AFTER UPDATE ON `tbl_sub_model_eng_trans_part`
 FOR EACH ROW 
    if NEW.engine_sk = 0 and NEW.trans_sk = 0
    then
        UPDATE tbl_sub_model tsm
        INNER JOIN tbl_fct_sub_eng_trans tfset ON tsm.sub_model_sk = tfset.sub_model_sk
        INNER JOIN tbl_sub_model_eng_trans_part tsmetp ON tfset.trans_sk = tsmetp.trans_sk
        SET tsm.last_modified_date = NOW()
        WHERE tsmetp.sub_model_sk=NEW.sub_model_sk;
    end if;

I get these two errors:

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 9

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 'end if' at line 1

回答1:

You forgot to change the delimiter, so MySQL thinks your first statement is this:

CREATE TRIGGER `trg_part_upd` AFTER UPDATE ON `tbl_sub_model_eng_trans_part`
 FOR EACH ROW 
    if NEW.engine_sk = 0 and NEW.trans_sk = 0
    then
        UPDATE tbl_sub_model tsm
        INNER JOIN tbl_fct_sub_eng_trans tfset ON tsm.sub_model_sk = tfset.sub_model_sk
        INNER JOIN tbl_sub_model_eng_trans_part tsmetp ON tfset.trans_sk = tsmetp.trans_sk
        SET tsm.last_modified_date = NOW()
        WHERE tsmetp.sub_model_sk=NEW.sub_model_sk;

Just add this before the code:

DELIMITER $$

... and this afterwards:

$$

... so MySQL can recognize the complete trigger as a single statement.

You can change $$ for your own choice.

Official docs give details on this in the Defining Stored Programs section.

回答2:

Try This:

DELIMITER $$
CREATE TRIGGER `trg_part_upd` AFTER UPDATE ON `tbl_sub_model_eng_trans_part`
 FOR EACH ROW BEGIN 
    IF NEW.engine_sk = 0 AND NEW.trans_sk = 0
    THEN
        UPDATE tbl_sub_model tsm
        INNER JOIN tbl_fct_sub_eng_trans tfset ON tsm.sub_model_sk = tfset.sub_model_sk
        INNER JOIN tbl_sub_model_eng_trans_part tsmetp ON tfset.trans_sk = tsmetp.trans_sk
        SET tsm.last_modified_date = NOW()
        WHERE tsmetp.sub_model_sk=NEW.sub_model_sk;
    END IF;
  END;
$$

DELIMITER ;

回答3:

The trigger is a source object, it has a body - one or more internal statements.

• If there are some statements in body, then body must be wrapped with BEGIN...END clause. In this case you may also need to use client DELIMITER command for the CREATE TRIGGER.
• If you had one statement in the body, then you could use syntax without BEGIN...END, and without DELIMITER command.