MySQL join 与where的执行顺序MySQL join 与where的执行顺序
MySQL join 与where的执行顺序-- 写法ok 先过滤后joinselect * from(select * from u1 where u1.id=3)t join u2 on t.id=u2.id;id name id(1) sex3 c 3 male-- 写法ok 先join后过滤select * from u1 join u2 on u1.id=u2.id where u1.id=3;id name id(1) sex3 c 3 male-- 写法oksel
