计算后没有自动更新数据库

Question

我有来自不同表格的分数计算。 问题是，当我插入新分数和最终分数改变时，数据库没有自动更新..

我尝试使用触发器但是我遇到了错误，因为我不知道如何实现它的正确方法..

$ firsttransgrade是最终得分..

这是我之前尝试的触发器

<?php include('../db.php'); $queryfirst = mysql_query("CREATE TRIGGER onupdate BEFORE UPDATE ON student_subject FOR EACH ROW BEGIN SET NEW.first = NEW.$firsttransgrade WHERE idnumber='$idnumber'               AND subject='$subject' AND section='$section' AND level='$level' AND year='$year' AND teacher='$login_session' ; END;") or die("Query failed: ".mysql_error());?>

这是错误

Query failed: 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 'WHERE idnumber='1111' AND subject='filipino' AND section='amihan' at line 4