-- From Where Select
select * from
(select sal as salary,comm as commission from emp ) x where salary<5000
-- Name Work as a Job
select ename +' Work as a'+job as msg from emp where deptno=10
-- 2000 UnderPaid 4k OverPaid OK
select ename,sal,
case when sal<2000 then 'UnderPaid'
when sal>=4000 then 'OverPaid'
else
'OK'
end
from emp
-- N newid()
--order by ， select
--order by ，
select top 5 ename from emp order by newid()
-- is null
select * from emp where comm is null
--
-- ：
--coalesce ， ， . ：[,kəuə'les] ：[,koə'lɛs]
select coalesce(comm, 1),empNo from emp
--
--
select ename,job
from emp
where deptno in(10,20)
--
select ename, job from emp order by substring(job,len(job)-2,2)
--select top 2 len(job)-2 from emp
--select top 2 job from emp
--☆☆☆☆☆ ☆☆☆☆☆ [ 0]
select ename ,sal,comm
from emp
order by 1 desc
-- ， ， case
select ename,sal,comm from
(
select ename ,sal,comm ,
case when comm is null then 0 else 1 end as A
from emp
) x
order by A desc ,comm desc
