标签：name from where sel rom ediff nbsp 计算 ted
select datediff(ward_hd,allen_hd)
from (
select hiredate as ward_hd
from emp
where ename=‘WARD‘
) x,
(select hiredate as allen_hd
from emp
where ename=‘ALLEN‘
)y;
标签：name from where sel rom ediff nbsp 计算 ted
原文地址：http://www.cnblogs.com/liang545621/p/6805635.html
