????????????????SQL Server ???sql??????????????:
????1????????????е?????
????-----------select * from ????
????-----------select all id??name from ????
????-----------select id??name from ????
????2????????????????????
????-----------select * from ??A????B where ??A.id=??B.id
????---------- select * from ??A inner join ??B on ??A.id=??B.id
????3?????????????????/??ι????
????----------- select distinct * from ??A
????-----------select distinct(???) from ??A
????4?????????
????-----------select count(*) from ??A
????-----------select count(1) from ??A
????-----------select count(???) from ??A
????-----------select count(distinct ???) from ??A
????5??????N??????
????-----------select top n * from ??A
????-----------select top (n) * from c order by id desc
????6??????е?in??not in ??exists?? notexists
????----------select * from ??A where not exists (select * from ??B where id =??A.id)
????----------select * from ??A where exists (select * from ??B where id =??A.id)
????---------select * from ??A where id in (select id from ??B)
????---------select * from ??A where id not in (select id from ??B)
????7?????????and??or???÷?
????--------select * from ??A where ???A='' and ???B=''
????--------select * from ??A where ???A='' or ???B=''
????8??union??union all???в???????
????--------select id?? name from ??A where ??? like '%'unionselect id?? ??? from ??A where id = 4 ---------------------?????????
????--------select * from??A where name like '%'union allselect * from ??A---------------------???????
????---------select * from ??Awhere ???like '%'intersectselect * from ??A--------------------------??????????????
????----------select * from ??Awhere ???like '%'exceptselect * from ??Awhere ???like '%' -------------?????????????
????9????????
????---------selectmax(???)??A
????---------select min(???)??A
????---------select count(???)??A
????---------select avg(???)??A
????---------select sum(???)??A
????---------select var(???)??A
????10?????????
????-------select dateAdd(day?? 3?? getDate())
????-------select dateAdd(year?? 3?? getDate())
????-------select dateAdd(hour?? 3?? getDate())
????---------------------??????????----------------
????----------select dateDiff(day?? '2016-01-01'?? getDate())
????----------select dateDiff(second?? '2016-01-0100:00:00'?? getDate())
????----------select dateDiff(hour?? '2016-01-0100:00:00'?? getDate())
????----------select dateName(month?? getDate())
????----------select dateName(minute?? getDate())
????----------select dateName(weekday?? getDate())
????---------select datePart(month?? getDate())
????---------select datePart(weekday?? getDate())
????---------select datePart(second?? getDate())
????---------select day(getDate())
????---------select day('2016-01-01')
????--------select month(getDate())
????--------select month('2016-01-01')
????--------select year(getDate())
????--------select year('2016-01-01')
????--------select getDate()
????--------select getUTCDate()
????11?????????
????-------select pi()
????-------select rand(100)?? rand(50)?? rand()?? rand()
????-------select round(rand()?? 3)?? round(rand(100)?? 5)
????-------select round(123.456?? 2)?? round(254.124?? -2)
????-------select round(123.4567?? 1?? 2)
????12???????
????------select len(?????)
????------select reverse(?????)
????------selectleft(??????? 4)
????------selectright(??????? 4)
????------select lower('abc')?? lower('ABC')
????------select upper('ABc')?? upper('abc')
????13???????????
????-------create database ??????
????14??????????
????------drop database ?????????
????15??????sql
????-----use master exes sp_addumpdevice '?????' ??'????????'??'??????'
????16?????????
????----- backup database pubs to'????????'
????17????????
????------create table ??????
????18???????
????------drop table??????
????19????????
????------alter table ?????? add column col ??????
????20?????????
????-------create view ???????
????21????????
????-----drop view???????
????22???????????
????-------select * into ??B from ??A
????------select top 0into ??B from ??A
????23??between???÷?
????------select * from ??A where time between time1 and time2
????-----select * from ??A where id between id1 and id2