--方法一：
select distinct name
from table
where name not in (
select distinct name f
rom table where fenshu<=80
)
--方法二：
select name from table
group by name
having min(fenshu)>80

delete tablename
where 自动编号 not in(
select min( 自动编号)
from tablename
group by 学号,姓名,课程编号,课程名称,分数)

select a.name, b.name
from team a, team b
where a.name < b.name

select a.* from TestDB a,
(
select Occmonth,max(DebitOccur) Debit101ccur
from TestDB
where AccID='101'
group by Occmonth) b
where a.Occmonth=b.Occmonth and a.DebitOccur>b.Debit101ccur

select year,
(select amount from   aaa m where month=1   and m.year=aaa.year) as m1,
(select amount from   aaa m where month=2   and m.year=aaa.year) as m2,
(select amount from   aaa m where month=3   and m.year=aaa.year) as m3,
(select amount from   aaa m where month=4   and m.year=aaa.year) as m4
from aaa group by year

--SQL:
select * into b from a where 1<>1--ORACLE:
create table b
As
Select * from a where 1=2

insert into b(a, b, c)
select d,e,f from a;

select a.title,a.username,b.adddate
from table a,(
select max(adddate) adddate
from table where table.title=a.title
) b

--SQL Server:
select a.a, a.b, a.c, b.c, b.d, b.f
from a LEFT OUTER JOIN b ON a.a = b.c--ORACLE：
select a.a, a.b, a.c, b.c, b.d, b.f from a ,b
where a.a = b.c(+)

--SQL Server
select * from 日程安排
where datediff('minute',开始时间,getdate())>5

--SQL Server:
Delete from info
where not exists (
select * from infobz
where info.infid=infobz.infid
)

update b set b.value=(
select a.value
from a where a.key=b.key)
where b.id in(
select b.id from b,a
where b.key=a.key);

create table tmp(Tdate varchar(10),Tresulte nchar(1));insert into tmp values('2019-05-09','胜');
insert into tmp values('2019-05-09','胜');
insert into tmp values('2019-05-09','负');
insert into tmp values('2019-05-09','负');
insert into tmp values('2019-05-10','胜');
insert into tmp values('2019-05-10','负');
insert into tmp values('2019-05-10','负');--方法一
select Tdate '日期',
sum(case when Tresulte ='胜' then 1 else 0 end)'胜',
sum(case when Tresulte ='负' then 1 else 0 end)'负'
from tmp group by Tdate ;
--方法二
select N.Tdate '日期',N.勝,M.負
from (
select Tdate ,count(*) '胜' from tmp where Tresulte ='胜' group by Tdate ) N
inner join
(
select Tdate ,count(*) '负' from tmp where Tresulte ='负' group by Tdate ) M
on N.Tdate =M.Tdate ;

select
(case when a>b then a else b end ),
(case when b>c then b esle c end)
from table_name

select * from tb
where datediff(dd,SendTime,getdate())=0

select
(case when 语文>=80 then '优秀'when 语文>=60 then '及格'else '不及格') as 语文,
(case when 数学>=80 then '优秀'when 数学>=60 then '及格'else '不及格') as 数学,
(case when 英语>=80 then '优秀'when 英语>=60 then '及格'else '不及格') as 英语,
from table

select a.dep,
sum(case when b.mon=1 then b.yj else 0 end) as '一月份',
sum(case when b.mon=2 then b.yj else 0 end) as '二月份',
sum(case when b.mon=3 then b.yj else 0 end) as '三月份',
sum(case when b.mon=4 then b.yj else 0 end) as '四月份',
sum(case when b.mon=5 then b.yj else 0 end) as '五月份',
sum(case when b.mon=6 then b.yj else 0 end) as '六月份',
sum(case when b.mon=7 then b.yj else 0 end) as '七月份',
sum(case when b.mon=8 then b.yj else 0 end) as '八月份',
sum(case when b.mon=9 then b.yj else 0 end) as '九月份',
sum(case when b.mon=10 then b.yj else 0 end) as '十月份',
sum(case when b.mon=11 then b.yj else 0 end) as '十一月份',
sum(case when b.mon=12 then b.yj else 0 end) as '十二月份',
from table2 a left join table1 b on a.dep=b.dep

--方法一
select id,Count（*)
from tb
group by id
having count(*)>1;
--方法二
select * from
(select count(ID) as count
from table
group by ID)T
where T.count>1

--连接查询
SELECT b.YEAR, SUM(a.salary) salary
FROM hello a, hello b
WHERE a.YEAR <= b.YEAR GROUP BY b.YEAR--子查询
select year ,
(select sum(salary)
from hello as B
where B.year<=A.year )
from hello as A