mySQL 触发错误代码 1064

Question

USE test;
CREATE TRIGGER AvgUpdateTrigger AFTER INSERT ON test.score
FOR EACH ROW
BEGIN
INSERT INTO test.average (test.average.TestID, test.average.TestAvg)
(SELECT test.score.TestID, avg(test.score.ScoreValue) FROM test.score GROUP BY test.score.TestID)
ON DUPLICATE KEY 
UPDATE test.average.TestAvg = (SELECT avg(test.score.ScoreValue) FROM test.score WHERE test.score.TestID = test.average.TestID GROUP BY test.score.TestID);
END;

当另一张表发生更改(分数)时，我试图更新一张表(平均)它告诉我添加一个分号，但正如你所看到的，已经有一个分号了

Answer 1

如果触发器(或任何存储过程)仅包含一条语句，则不需要 BEGIN 和 END:

CREATE TRIGGER AvgUpdateTrigger AFTER INSERT ON test.score
FOR EACH ROW
    INSERT INTO test.average (TestID, TestAvg)
        SELECT test.score.TestID, avg(test.score.ScoreValue)
        FROM test.score
        GROUP BY test.score.TestID
        ON DUPLICATE KEY UPDATE
            test.average.TestAvg = VALUES(TestAvg);

我还用 VALUES(TestAvg) 替换了子查询，因为已经选择了该值。