Mysql优化
2022-09-0288
先查出所有A中需要连接的字段
select [ ] from tableA where [ ]
然后再去用B表in 这些
select [ ] from tableB where C in (select [ ] from tableA where [ ] )
然后 select A.*,B.* from A,B where [] in () and a.x = b.x
先查出所有A中需要连接的字段
select [ ] from tableA where [ ]
然后再去用B表in 这些
select [ ] from tableB where C in (select [ ] from tableA where [ ] )
然后 select A.*,B.* from A,B where [] in () and a.x = b.x