~~~~~急急急急急急 两个查询的 比较 高手 赐教 谢谢 ~~~~~~~~~~~
create table work2.temp2 as select
a.datetime,
a.slabweiuse,
b.shift
from bpciqv.sufuc004 a, bpciqv.shiftconver b
where b.timefrom< a.datetime <b.timeto;
create table work2.temp2 as select
a.datetime,
a.slabweiuse,
b.shift
from bpciqv.sufuc004 a left join bpciqv.shiftconver b
on b.timefrom< a.datetime <b.timeto;
left join 和 直接 bpciqv.sufuc004 a, bpciqv.shiftconver b
有什么区别
谢谢 高手详解
哪个速度快