MySQL 5.1 中需要一个抽象触发器来更新审核日志

Question

我需要一种方法来检查表中已更改的任何条目并将其传递到审核日志中。它需要从表结构中抽象出来。

例如：

CREATE TRIGGER table1_update 
BEFORE UPDATE ON table1 
FOR EACH ROW BEGIN
  DECLARE i_column_name varchar(32);
  DECLARE done INT;
  DECLARE cursor1 CURSOR FOR SELECT column_name FROM information_schema.columns WHERE table_name = 'table1';
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

  OPEN cursor1;
  REPEAT
    FETCH cursor1 INTO i_column_name;
    IF NOT done THEN

      --pass the variable column_name and its old.i_column_name and new.i_column_name values to the audit table

    END IF;
  UNTIL done END REPEAT;
  CLOSE cursor1;
END$$

我们有太多的表需要审核以自定义构建每个 INSERT、UPDATE 和 DELETE 触发器。我尝试了很多事情，但我想我运气不好。有人有什么想法吗？

Answer 1

您不能拥有抽象触发器，它必须在特定表上定义。最接近的方法是将触发器的代码放入存储过程中，然后每个表的触发器将只调用该过程。

CREATE PROCEDURE audit_update (IN tablename VARCHAR(64))
BEGIN
  DECLARE  i_column_name varchar(32);
  DECLARE done INT;
  DECLARE cursor1 CURSOR FOR SELECT column_name FROM information_schema.columns WHERE table_name = tablename;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

  OPEN cursor1;
  REPEAT
    FETCH cursor1 INTO i_column_name;
    IF NOT done THEN

      --pass the variable column_name and its old.i_column_name and new.i_column_name values to the audit table

    END IF;
  UNTIL done END REPEAT;
  CLOSE cursor1;
END


CREATE TRIGGER table1_update 
BEFORE UPDATE ON table1 
FOR EACH ROW BEGIN
  CALL audit_update('table1');
END

您应该能够轻松地编写一些脚本，使用 information_schema 或类似的内容为所有表创建触发器。

SELECT CONCAT('CREATE TRIGGER ', table_name, '_update BEFORE UPDATE ON ', table_name, ...) FROM information_schema...