Temp

 http://www.teecool.com/post/2007071808.html

http://blog.csdn.net/zhangyj_315/category/375024.aspx

http://blog.csdn.net/m_yeah/archive/2009/02/19/3908885.aspx

 

select datepart(dd,
                dateadd(dd,
                        -1,
                        dateadd(mm,1,cast(cast(year(getdate()) as varchar)+'-'+cast(month(getdate()) as varchar)+'-01' as datetime))))

go

declare @now  datetime
set @now = '2009-07-21'

select day(dateadd(dd,-1,dateadd(mm,1,cast(cast(year(@now) as varchar) + '-' + cast(month(@now) as varchar) + '-01' as datetime))))


select day(dateadd(dd,-1,dateadd(mm,1,cast(cast(year(getdate()) as varchar)+'-'+cast(month(getdate()) as varchar)+'-01' as datetime))))
go

create table BookInfo(
BookId int,
BookName varchar(50),
Price float)

insert BookInfo values(1,'Windows Internals',20)
insert BookInfo values(2,'Linker & Loader',10)
insert BookInfo values(3,'Design Pattern',5)
insert BookInfo values(4,'Design Pattern',null)

insert BookInfo(BookId,BookName) values(5,'Common Sence')

select BookId,BookName,Price
from BookInfo


select BookId,BookName,Price=case when Price is null then 'UnKnown' when Price between 10 and 20 then '10-20' else 'Others' end
from BookInfo


select BookName
from( select BookName, count(BookName) as num
      from BookInfo
      group by BookName) T1
where T1.num >= 2

select * from BookInfo

select row_number() over( order by Price asc) as line_no , *
from BookInfo

select BookId, BookName,Price into #Temp1
from(
select row_number() over( order by Price asc) as line_no , *
from BookInfo) T1
where line_no between 2 and 4

select * from #temp1

truncate table BookInfo

select * into #Temp2 from BookInfo

insert into BookInfo
select * from #temp1

insert into BookInfo
select * from #temp2

drop table #temp1
drop table #temp2

 

Create table T1(
id int,
num int)

create table T2(
id int,
s_name varchar(20))

insert into T1 values(1,100)
insert into T1 values(2,200)
insert into T1 values(3,300)
insert into T1 values(4,400)

insert into T2 values(3,'AAAA');
insert into T2 values(4,'BBBB');
insert into T2 values(5,'CCCC');
insert into T2 values(6,'DDDD');

select * from T1
select * from T2
select * from T1 inner join T2 on T1.id = T2.id
select * from T1  join T2 on T1.id = T2.id
select * from T1 left join T2 on T1.id = T2.id
select * from T1 left outer join T2 on T1.id = T2.id
select * from T1 right join T2 on T1.id = T2.id
select * from T1 right outer join T2 on T1.id = T2.id