Question

我试图在我的mysql数据库中创建一个触发器但是我一直收到错误。这是我的查询：

CREATE TRIGGER update_counters AFTER INSERT ON cheats_main FOR EACH ROW
BEGIN
    DELETE FROM meta_info;
    INSERT INTO meta_info (system_id, system, game_count, cheat_count) VALUES (
        SELECT id, system,
        (SELECT count(g1.id) FROM cheats_games g1 WHERE g1.system = s.id) AS games_counter,
        (SELECT count(c2.id) FROM cheats_main c2 JOIN cheats_games g2 ON g2.id = c2.game_id
        WHERE g2.system = s.id) AS cheats_counter 
        FROM systeme AS s
    );
END;

MySQL表＆＃34; meta_info＆＃34;有这种结构：

system_id | system | game_count | cheat_count | created

我不断得到的错误是：

MySQL说：文档1064 - 你有 SQL语法中的错误;查看与您的手册相对应的手册 MySQL服务器版本，用于在＆＃39;＆＃39;附近使用正确的语法在第3行

第3行是：

DELETE FROM meta_info;

当我删除此行时，我收到此错误：

1064 - 您的SQL语法出错;检查与MySQL服务器版本对应的手册，以获得正确的语法靠近＆＃39; SELECT id，system，（SELECT count（g1.id）FROM cheats_games g1 WHERE g1.system＆＃39; at line 4

在这种情况下，第4行是：

SELECT id, system (...)

内部SELECT工作得很好。我得到一个包含这些列的结果表：

id | system | games_counter | cheats_counter

感谢任何帮助。谢谢。

Answer 1

您需要定义另一个分隔符，而不是;。否则，DB将在第一个;处停止触发器定义，这将是不完整的

delimiter |
CREATE TRIGGER update_counters AFTER INSERT ON cheats_main FOR EACH ROW
BEGIN
    DELETE FROM meta_info;
    INSERT INTO meta_info (system_id, system, game_count, cheat_count)
        SELECT id, system,
        (SELECT count(g1.id) FROM cheats_games g1 WHERE g1.system = s.id) AS games_counter,
        (SELECT count(c2.id) FROM cheats_main c2 JOIN cheats_games g2 ON g2.id = c2.game_id
        WHERE g2.system = s.id) AS cheats_counter 
        FROM systeme AS s;
END
|
delimiter ;

如果你在insert语句中使用select，那么就像这样使用它

insert into t1(col1, col2)
select a, b from t2

创建TRIGGER给出错误（MySQL）

1 个答案: