说明：复制表(只复制结构,源表名：a 新表名：b)  
select * into b from a where 1<>1


说明：拷贝表(拷贝数据,源表名：a 目标表名：b)
insert into b(a, b, c) select d,e,f from b;


说明：显示文章、提交人和最后回复时间
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b


说明：外连接查询(表名1：a 表名2：b)
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c


说明：日程安排提前五分钟提醒
select * from 日程安排 where datediff('minute',f开始时间,getdate())>5


说明：两张关联表，删除主表中已经在副表中没有的信息
delete from info where not exists ( select * from infobz where info.infid=infobz.infid )


说明：--  

SQL:  

Select A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE  

FROM TABLE1,  

(Select X.NUM, X.UPD_DATE, Y.UPD_DATE PREV_UPD_DATE  

FROM (Select NUM, UPD_DATE, INBOUND_QTY, STOCK_ONHAND  

FROM TABLE2  

Where TO_CHAR(UPD_DATE,'YYYY/MM') = TO_CHAR(SYSDATE, 'YYYY/MM')) X,  

(Select NUM, UPD_DATE, STOCK_ONHAND  

FROM TABLE2  

Where TO_CHAR(UPD_DATE,'YYYY/MM') =  

TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, 'YYYY/MM') || '/01','YYYY/MM/DD') - 1, 'YYYY/MM') ) Y,  

Where X.NUM = Y.NUM （+）  

AND X.INBOUND_QTY + NVL(Y.STOCK_ONHAND,0) <> X.STOCK_ONHAND ) B  

Where A.NUM = B.NUM


说明：--  
select * from studentinfo where not exists(select * from student where studentinfo.id=student.id) and 系名称='"&strdepartmentname&"' and 专业名称='"&strprofessionname&"' order by 性别,生源地,高考总成绩


从数据库中去一年的各单位电话费统计(电话费定额贺电化肥清单两个表来源）  

Select a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS telyear,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '04', a.factration)) AS APR,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '05', a.factration)) AS MAY,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '07', a.factration)) AS JUL,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '08', a.factration)) AS AGU,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '09', a.factration)) AS SEP,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '10', a.factration)) AS OCT,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,  

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '12', a.factration)) AS DEC  

FROM (Select a.userper, a.tel, a.standfee, b.telfeedate, b.factration  

FROM TELFEESTAND a, TELFEE b  

Where a.tel = b.telfax) a  

GROUP BY a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy')


说明：四表联查问题
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....  


说明：得到表中最小的未使用的ID号


Select (CASE WHEN EXISTS(Select * FROM Handle b Where b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleID  FROM Handle Where NOT HandleID IN (Select a.HandleID - 1 FROM Handle a)


一个SQL语句的问题:行列转换
select * from v_temp
上面的视图结果如下:
user_name role_name
-------------------------
系统管理员 管理员  
feng 管理员  
feng 一般用户  
test 一般用户  
想把结果变成这样:
user_name role_name
---------------------------
系统管理员 管理员  
feng 管理员,一般用户  
test 一般用户
===================
create table a_test(name varchar(20),role2 varchar(20))
insert into a_test values('李','管理员')
insert into a_test values('张','管理员')
insert into a_test values('张','一般用户')
insert into a_test values('常','一般用户')

create function join_str(@content varchar(100))
returns varchar(2000)
as
begin
declare @str varchar(2000)
set @str=''
select @str=@str+','+rtrim(role2) from a_test where [name]=@content
select @str=right(@str,len(@str)-1)
return @str
end
go

--调用：
select [name],dbo.join_str([name]) role2 from a_test group by [name]

--select distinct name,dbo.uf_test(name) from a_test


快速比较结构相同的两表
结构相同的两表，一表有记录3万条左右，一表有记录2万条左右，我怎样快速查找两表的不同记录？
============================
给你一个测试方法，从northwind中的orders表取数据。
select * into n1 from orders
select * into n2 from orders

select * from n1
select * from n2

--添加主键，然后修改n1中若干字段的若干条
alter table n1 add constraint pk_n1_id primary key (OrderID)
alter table n2 add constraint pk_n2_id primary key (OrderID)

select orderID from (select * from n1 union select * from n2) a group by orderID having count(*) > 1

应该可以，而且将不同的记录的ID显示出来。
下面的适用于双方记录一样的情况，

select * from n1 where orderid in (select orderID from (select * from n1 union select * from n2) a group by orderID having count(*) > 1)  
至于双方互不存在的记录是比较好处理的
--删除n1,n2中若干条记录
delete from n1 where orderID in ('10728','10730')
delete from n2 where orderID in ('11000','11001')

--*************************************************************
-- 双方都有该记录却不完全相同
select * from n1 where orderid in(select orderID from (select * from n1 union select * from n2) a group by orderID having count(*) > 1)
union
--n2中存在但在n1中不存的在10728,10730
select * from n1 where orderID not in (select orderID from n2)
union
--n1中存在但在n2中不存的在11000,11001
select * from n2 where orderID not in (select orderID from n1)


四种方法取表里n到m条纪录：

1.
select top m * into 临时表(或表变量) from tablename order by columnname -- 将top m笔插入
set rowcount n
select * from 表变量 order by columnname desc


2.
select top n * from (select top m * from tablename order by columnname) a order by columnname desc


3.如果tablename里没有其他identity列，那么：
select identity(int) id0,* into #temp from tablename

取n到m条的语句为：
select * from #temp where id0 >=n and id0 <= m

如果你在执行select identity(int) id0,* into #temp from tablename这条语句的时候报错,那是因为你的DB中间的select into/bulkcopy属性没有打开要先执行：
exec sp_dboption 你的DB名字,'select into/bulkcopy',true