慕移动4157097
2017-02-28 17:17
select b.user_name,b.over,a.over from user1 as a right join user2 as b on a.user_name=b.user_name where a.user_name is not null.
as是给字段起别名,而表的别名直接在原表名后加空格加别名即可
MySQL开发技巧(一)
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