我在phpmyadmin中有触发器代码

BEGIN
    DECLARE videTimeSum,channel INT;
    DECLARE done INT DEFAULT FALSE;
    DECLARE cur1 CURSOR FOR Select  sum(videotime) - COALESCE(sum( TIMESTAMPDIFF(Minute,datestart, now() ) ),0)  as videot,channelnumber from videos where flag='0' and channelnumber in (Select channelnumber from channels where flag='0') group by channelnumber order by videot asc limit 1;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
    If(New.channelnumber is NULL or New.channelnumber ='')
            then   
                SET @channel=(Select channelnumber from channels where flag='0' and channelnumber not in (Select channelnumber from videos where dateend is NULL) limit 1);
                IF(@channel is not NULL and @channel <>'')
                    then 
                        SET New.channelnumber=@channel;
                        SET New.playdate=now() + INTERVAL 1 MINUTE;
                        SET New.enddate=now() + INTERVAL New.videotime MINUTE;
                ELSE
                    OPEN cur1;
                    read_loop: LOOP
                        FETCH cur1 INTO videTimeSum,channel;
                        IF done THEN
                            LEAVE read_loop;
                        ELSE
                            SET New.channelnumber=channel; 
                            SET @videTimeSum=videTimeSum;
                            SET New.playdate = now() + INTERVAL @videTimeSum MINUTE;
                            SET New.enddate = now() + INTERVAL (@videTimeSum + New.videotime)  MINUTE;
                        END IF;
                    END LOOP;
                    CLOSE cur1;
                END IF;
    END IF;
    
END

phpmyadmin在DECLARE附近显示问题
请帮助我克服这个问题
我有phpmyadmin版本4.5.4.1deb2ubuntu2.1