摘要: 一面 (1) select * from A left join B on A.id = B.id; 问语句的查询结果 A: id name 1 a 1 b 2 c 3 d B: id name 1 e 1 f 4 g (2)left join, right join, inner join和一个另 阅读全文
posted @ 2020-03-27 17:55 好好学习啊— 阅读(141) 评论(0) 推荐(0)