1,改变数据库状态
增:insert
删:delete
改:update
2不改变数据库状态
查:select ..输出..from..获取数据... where..过滤...group by ...分组...having...过滤...order by...排序....limit...限定个数...
执行顺序1from,2 where 3 group by 4 select 5 having 6 order by 7 limit
微信扫一扫
1,改变数据库状态
增:insert
删:delete
改:update
2不改变数据库状态
查:select ..输出..from..获取数据... where..过滤...group by ...分组...having...过滤...order by...排序....limit...限定个数...
执行顺序1from,2 where 3 group by 4 select 5 having 6 order by 7 limit
相关推荐