1

由于 SQL 没有语句，我们如何在不知道表列 [和表名]的情况下验证类型中从对象到对象的FOR-EACH每个值是否存在差异？OLDNEWAFTER UPDATETRIGGER

今天的例子：

CREATE TRIGGER `audit_events_ugly`
AFTER UPDATE ON `accounts`
FOR EACH ROW
BEGIN
       DECLARE changes VARCHAR(8000);
       IF OLD.user_name <> NEW.user_name THEN
            SET changes = 'user_name from % to %';
       END IF;
       IF OLD.user_type <> NEW.user_type THEN
            SET changes = CONCAT(changes, ', user_type from % to %');
       END IF;
       IF OLD.user_email <> NEW.user_email THEN
            SET changes = CONCAT(changes, ', user_email from % to %');
       END IF;
       CALL reg_event(how_canI_get_tableName?, @user_id, changes);
       -- and that can go on and on... differently for every table.
END;

我希望它可以是示例：

CREATE TRIGGER `audit_events_nice`
AFTER UPDATE ON `accounts`
FOR EACH ROW
BEGIN
       DECLARE changes VARCHAR(8000);
       DECLARE N INT DEFAULT 1;
       FOREACH OLD, NEW as OldValue, NewValue 
       BEGIN
              IF OldValue <> NewValue THEN
              SET changes = CONCAT(changes, ', column N: % to %');
              SET N = N + 1;
       END IF;
       CALL reg_event(how_canI_get_tableName?, @user_id, changes);
       -- now I can paste this code in every table that is audited..
END;

有任何想法吗？同时， FOREACH，阵列...

4

1 回答 1

1

我认为您不能直接在触发级别的 for 循环中执行此操作。

但是，您可以使用脚本来生成触发代码。每次向表中添加/删除字段时（通常不经常），您都需要重新生成它。

于 2016-02-25T16:11:46.343 回答