如何查找过去一小时内添加或更新的MySQL视图或触发器？

Question

我需要跟踪数据库更改.可以从相关的INFORMATION_SCHEMA表中获取表,函数和存储过程的此信息.但在视图和触发器的情况下,似乎没有CREATED或MODIFIED DateTime的数据.怎么能实现这一目标？

Answer 1

对于触发器的"创建"日期/时间,有一个CREATED字段INFORMATION_SCHEMA.TRIGGERS.但根据MySQL文档,这只能在MySQL 5.7.2或更高版本中正确填充:

CREATED:创建触发器的日期和时间.这是在MySQL 5.7.2或更高版本中创建的触发器的TIMESTAMP(2)值(以百分之几秒为单位),对于在5.7.2之前创建的触发器为NULL.

但不幸的是,没有相应的"更新"或"删除"日期/时间列,并且该INFORMATION_SCHEMA.VIEWS表没有任何这些.我对可能的解决方法的第一个想法是在相关INFORMATION_SCHEMA表上创建触发器,但不幸的是,这似乎不可能,因为INFORMATION_SCHEMA表实际上更像是"视图"(但不是基于实际表).因此,以下"次佳"解决方案......

解决方法:"快照"表

使用每小时运行的MySQL事件调度程序创建一个计划事件,并运行查询以将INFORMATION_SCHEMA.TRIGGERS和INFORMATION_SCHEMA.VIEWS表的内容复制到本地数据库中的"快照"表中:

-- Remove existing event of this name if there is one
DROP EVENT IF EXISTS update_snapshots;

DELIMITER $$
CREATE EVENT update_snapshots ON SCHEDULE EVERY 1 HOUR 
    DO BEGIN
        -- Drop the current snapshot table (if there is one)
        DROP TABLE IF EXISTS triggers_snapshot;
        DROP TABLE IF EXISTS views_snapshot;

        -- Recreate snapshot tables
        CREATE TABLE triggers_snapshot AS SELECT * FROM INFORMATION_SCHEMA.TRIGGERS;
        CREATE TABLE views_snapshot AS SELECT * FROM INFORMATION_SCHEMA.VIEWS;
    END $$
DELIMITER ;

-- Turn the MySQL event scheduler on
SET GLOBAL event_scheduler = ON;

-- Show all events (to check it was created successfully and its status)
SHOW EVENTS;

然后,在任何点的电流INFORMATION_SCHEMA表可以被查询,并与使用技术如快照这一个:

SELECT  'new' AS `status`, s.*
FROM    INFORMATION_SCHEMA.TRIGGERS s
WHERE   ROW(s.TRIGGER_CATALOG, s.TRIGGER_SCHEMA, s.TRIGGER_NAME, s.EVENT_MANIPULATION,
            s.EVENT_OBJECT_CATALOG, s.EVENT_OBJECT_SCHEMA, s.EVENT_OBJECT_TABLE,
            s.ACTION_ORDER, s.ACTION_CONDITION, s.ACTION_STATEMENT, s.ACTION_ORIENTATION,
            s.ACTION_TIMING, s.ACTION_REFERENCE_OLD_TABLE, s.ACTION_REFERENCE_NEW_TABLE,
            s.ACTION_REFERENCE_OLD_ROW, s.ACTION_REFERENCE_NEW_ROW, s.CREATED, s.SQL_MODE,
            s.DEFINER, s.CHARACTER_SET_CLIENT, s.COLLATION_CONNECTION, 
            s.DATABASE_COLLATION) NOT IN (SELECT * FROM triggers_snapshot)
UNION ALL
SELECT  'old' AS `status`, t.*
FROM    triggers_snapshot t
WHERE   ROW(t.TRIGGER_CATALOG, t.TRIGGER_SCHEMA, t.TRIGGER_NAME, t.EVENT_MANIPULATION,
            t.EVENT_OBJECT_CATALOG, t.EVENT_OBJECT_SCHEMA, t.EVENT_OBJECT_TABLE,
            t.ACTION_ORDER, t.ACTION_CONDITION, t.ACTION_STATEMENT, t.ACTION_ORIENTATION,
            t.ACTION_TIMING, t.ACTION_REFERENCE_OLD_TABLE, t.ACTION_REFERENCE_NEW_TABLE,
            t.ACTION_REFERENCE_OLD_ROW, t.ACTION_REFERENCE_NEW_ROW, t.CREATED, t.SQL_MODE,
            t.DEFINER, t.CHARACTER_SET_CLIENT, t.COLLATION_CONNECTION, 
            t.DATABASE_COLLATION) NOT IN (SELECT * FROM INFORMATION_SCHEMA.TRIGGERS)

...和...

SELECT  'new' AS `status`, s.*
FROM    INFORMATION_SCHEMA.VIEWS s
WHERE   ROW(s.TABLE_CATALOG, s.TABLE_SCHEMA, s.TABLE_NAME, s.VIEW_DEFINITION,
            s.CHECK_OPTION, s.IS_UPDATABLE, s.DEFINER, s.SECURITY_TYPE,
            s.CHARACTER_SET_CLIENT, s.COLLATION_CONNECTION)
        NOT IN (SELECT * FROM views_snapshot)
UNION ALL
SELECT  'old' AS `status`, t.*
FROM    views_snapshot t
WHERE   ROW(t.TABLE_CATALOG, t.TABLE_SCHEMA, t.TABLE_NAME, t.VIEW_DEFINITION,
            t.CHECK_OPTION, t.IS_UPDATABLE, t.DEFINER, t.SECURITY_TYPE,
            t.CHARACTER_SET_CLIENT, t.COLLATION_CONNECTION)
        NOT IN (SELECT * FROM INFORMATION_SCHEMA.VIEWS)

限制

这些不会准确地告诉您何时进行了更改并且没有完全覆盖最后一小时 - 仅限于自上次快照以来的时间,这可能是过去一小时内的任何时间.如果需要更高的准确度,则可以减少快照间隔 - 但这会增加复杂性,因为可能需要维护多个快照并使用正确的快照进行比较.