MySQL Trigger - How to concatenate variable with the query?

Question

Value is not coming in @id as how to concat id variable in query

DELIMITER $$

CREATE TRIGGER update_trigger
AFTER INSERT ON asterisk.queue_log
FOR EACH ROW
BEGIN


 SET @id = (select callid from asterisk.queue_log where event="TRANSFER" and callid=(select callid from asterisk.queue_log
order by id desc limit 1));

SET @agentid = (select agent from asterisk.queue_log where event="TRANSFER" and callid=(select callid from
asterisk.queue_log order by id desc limit 1));

update Feedback.Feedback_Data set Agent_Id=@agentid where Call_Id=@id;

END $$
DELIMITER ;

Answer 1

There are two methods, first you can run trigger like below

DELIMITER $$
    CREATE TRIGGER Feedback
    AFTER INSERT ON queue_log
    FOR EACH ROW
    BEGIN
    DECLARE v_id varchar(32);
    DECLARE v_agentid varchar(32);
    SELECT callid, agent INTO v_id, v_agentid
    FROM queue_log
    WHERE event="TRANSFER"
    ORDER BY id desc limit 1;

    update Feedback_Data set Agent_Id=v_agentid where Call_Id=v_id;

    END $$
 DELIMITER ;

 

And the other method is calling external program and do what you want below is the way

http://answergig.com/798/how-to-execute-call-an-external-program-from-mysql-trigger?