Question

我有两个表：players和history_of_players。

我想为玩家制作某种历史记录，所以如果有人在玩家表中更新'club'，我希望将旧数据（旧俱乐部）保存到'history_of_players' {{1} }}，'player_ID'和'old_club'（实际年份）。

Answer 1

暂时没有使用MySQL，但这应该是你要找的（如果每个player_ID的播放器表中只有一行）：

delimiter //
CREATE TRIGGER historise BEFORE UPDATE ON players
  FOR EACH ROW
     BEGIN
       INSERT INTO history_of_players (player_ID, old_club, year)
       SELECT player_ID, old_club, year FROM players
       WHERE player_ID = OLD.player_ID;
     END;//
delimiter ;

Answer 2

您可能希望在players表上创建触发器。例如：

DELIMITER $$
CREATE TRIGGER playersHistoryTrigger
AFTER UPDATE ON players
FOR EACH ROW BEGIN
    INSERT INTO playersHistory
    VALUES (NEW.ID, NEW.Name, ...);
END$$
DELIMITER ;

Answer 3

这可以通过触发器完成。

delimiter //
CREATE TRIGGER playerup BEFORE UPDATE ON players
    FOR EACH ROW
    BEGIN
        INSERT INTO history_of_players (player_ID, old_club, date)
        VALUES (NEW.player_ID, OLD.club, CURDATE());
    END;//

UPDATE上的SQL将旧数据保存到另一个表中

3 个答案: