SQL语句先前写的时候,很容易把一些特殊的用法忘记,我特此整理了一下SQL语句操作。 Z0HfrK#oU
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一、基础 dt&m YSZ}
1、说明:创建数据库 0z&]imU
CREATE DATABASE database-name vZMb/}-o
2、说明:删除数据库 LtIp,2GP&_
drop database dbname B'}h6ZH
3、说明:备份sql server gySCK-(y
--- 创建 备份数据的 device >T84NFdz+
USE master 3v\69s
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' U'~M(9uv:
--- 开始 备份 <@:RS$"i
BACKUP DATABASE pubs TO testBack by07l5
4、说明:创建新表 ]R%[cr
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) tVfZ~qJ
根据已有的表创建新表: \LuaI
A:create table tab_new like tab_old (使用旧表创建新表) jW]Q-
B:create table tab_new as select col1,col2... from tab_old definition only tb$I8T
5、说明:删除新表 xqm-m
drop table tabname +4L]Z;k
6、说明:增加一个列 x[u4>f
Alter table tabname add column col type xER-TT#S
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 3CL1Z\8To
7、说明:添加主键: Alter table tabname add primary key(col) Fnqj^5
说明:删除主键: Alter table tabname drop primary key(col) 2|`7_*\
8、说明:创建索引:create [unique] index idxname on tabname(col....) R+sv? 4k
删除索引:drop index idxname
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注:索引是不可更改的,想更改必须删除重新建。 S\76`Ot
9、说明:创建视图:create view viewname as select statement r+TvC{
删除视图:drop view viewname c,>y1%V*S{
10、说明:几个简单的基本的sql语句 %f)%FN.S
选择:select * from table1 where 范围 h2jrO9
插入:insert into table1(field1,field2) values(value1,value2) xAwP
删除:delete from table1 where 范围 w{8O$4
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更新:update table1 set field1=value1 where 范围 y^0
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查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ^O0trM>h-
排序:select * from table1 order by field1,field2 [desc] 8I8{xt4
总数:select count as totalcount from table1 xe"A;6H
求和:select sum(field1) as sumvalue from table1 5J-slNNCQ
平均:select avg(field1) as avgvalue from table1 ~"J7=u1o
最大:select max(field1) as maxvalue from table1 .R^R32ln
最小:select min(field1) as minvalue from table1 =W*Ro+wWb
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11、说明:几个高级查询运算词 }!uwWBw`
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A: UNION 运算符 t5CJG '!ql
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 ~@#s<a,%;
B: EXCEPT 运算符 %)ri:Q q
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 |.OS7Gt?
C: INTERSECT 运算符 `#*`hH8
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 }wB!Bx2
注:使用运算词的几个查询结果行必须是一致的。 :FUxe kz
12、说明:使用外连接 Ts\PZQ!q
A、left outer join: B.A;1VE5
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 =qvn?I^/
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c nP&6i5s%
B:right outer join: '/s/o]'sUd
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 eN'b"_D
C:full outer join: ],
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全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 hbe";(
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二、提升 |H(i)yu"5'
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ,Yn$X
法一:select * into b from a where 1<>1 "r=p/"4D
法二:select top 0 * into b from a n5 <B*
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) UGxF}Q
insert into b(a, b, c) select d,e,f from b; |hS^eK_
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 33ZHrZ
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 !gL1
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 4~AY:
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4、说明:子查询(表名1:a 表名2:b) \j<aFOT(
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) A 4*D3\>%u
5、说明:显示文章、提交人和最后回复时间 Z6zLL
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b (QdLz5\
6、说明:外连接查询(表名1:a 表名2:b) RA!8AS?
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c tb>Q#QB&u
7、说明:在线视图查询(表名1:a ) Y=i_2R2e2
select * from (SELECT a,b,c FROM a) T where t.a > 1; _&N:%;9uD
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 g*-}9~
select * from table1 where time between time1 and time2 >[N6_*K]
select a,b,c, from table1 where a not between 数值1 and 数值2
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9、说明:in 的使用方法 /g1;`F(MS/
select * from table1 where a [not] in ('值1','值2','值4','值6') 7H4\AG\>
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ]M 2n%9
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) Uh XVeGO
11、说明:四表联查问题: gk}.LE
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 ..... <vzU}JA\
12、说明:日程安排提前五分钟提醒 cpH*!*S
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 (SCZ.G(>
13、说明:一条sql 语句搞定数据库分页 K#N5S]2yb
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 s]HJcgI
14、说明:前10条记录 5>:p'zI
select top 10 * form table1 where 范围 ivSpi?
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) _QtW)\)5\
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ,!^g8zO
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 {)4@rM
(select a from tableA ) except (select a from tableB) except (select a from tableC) u$
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17、说明:随机取出10条数据 uZP(-}
select top 10 * from tablename order by newid() CX 7eCo
18、说明:随机选择记录 QZ5%nJme_
select newid() QvzE:]pyi
19、说明:删除重复记录 m[w~h\FS
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Va/}|&9
20、说明:列出数据库里所有的表名 ioslarw1J
select name from sysobjects where type='U' }cIj1:
21、说明:列出表里的所有的 j[=P3Z0q
select name from syscolumns where id=object_id('TableName') +p-S36K~,7
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 2bf#L?5g/
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type rY"EW"y
显示结果: |vj!,b88n#
type vender pcs ^Uldyv/
电脑 A 1 c-[IgX e
电脑 A 1 n* z;%'0
光盘 B 2 'fIG$tr9X
光盘 A 2 kCKCJ}N
手机 B 3 YY$O"!."
手机 C 3 7D4I>N'T
23、说明:初始化表table1 6}_J;g\|
TRUNCATE TABLE table1 =V^8RlBi
24、说明:选择从10到15的记录 \U?{m)N
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc cV* 0+5
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三、技巧 Eqh&<]q
1、1=1,1=2的使用,在SQL语句组合时用的较多 5dLb`Gf
"where 1=1" 是表示选择全部 "where 1=2"全部不选, =(,dI[v
如: h='@Q_1Sb
if @strWhere !='' T)cbpkH4
begin }}v28"\TA
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ePI)~
end h{Y#. j~aS
else B=2f-o
begin 3q1u9`4;
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' Il#9t?/
end ;<v9i#K5
我们可以直接写成 K/LoHWy+n*
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ,:3Di (
2、收缩数据库 "cX*GTNi8
--重建索引 { FM:\/
DBCC REINDEX s KOy6v
DBCC INDEXDEFRAG PF-"^2&_
--收缩数据和日志 J_ `\}55n
DBCC SHRINKDB _ 6'HBE
DBCC SHRINKFILE }MV=t7x9+
3、压缩数据库 w77"?kJ9X
dbcc shrinkdatabase(dbname) ,xIWyI.
4、转移数据库给新用户以已存在用户权限 qXQ7Jg9
exec sp_change_users_login 'update_one','newname','oldname' RLbxNn
go jiAN8t*P
5、检查备份集 2aO.t
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 38O_PK
6、修复数据库 6\?<:Qto
ALTER DATABASE [dvbbs] SET SINGLE_USER (cqVCys
GO T>s3s5Y
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK SgPvQ'\
GO `}fwR
ALTER DATABASE [dvbbs] SET MULTI_USER Zae$M0)
GO +t PqU6
7、日志清除 |0/~7l
SET NOCOUNT ON V$fvf#T
DECLARE @LogicalFileName sysname, AIFI@#3
@MaxMinutes INT, Wi(Ac8uh
@NewSize INT TwXqk>J
USE tablename -- 要操作的数据库名 + %07J6
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 o@KK/f
@MaxMinutes = 10, -- Limit on time allowed to wrap log. weky
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@NewSize = 1 -- 你想设定的日志文件的大小(M) DJf!{:b)
-- Setup / initialize *R6Ed
DECLARE @OriginalSize int %2D9]L2Up
SELECT @OriginalSize = size P>3
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FROM sysfiles \4OX]{
WHERE name = @LogicalFileName nB1[OB{
SELECT 'Original Size of ' + db_name() + ' LOG is ' + .d>TU bR;
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + G\1\L*+0
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' %^$7z,>;
FROM sysfiles 5L4{8X0X8
WHERE name = @LogicalFileName 9vZD?6D,n
CREATE TABLE DummyTrans zn'F9rWx>
(DummyColumn char (8000) not null) Akbt%&
DECLARE @Counter INT, hf~'EdU
@StartTime DATETIME, usR:-1{
@TruncLog VARCHAR(255) aqk0+
SELECT @StartTime = GETDATE(), yy%'9E ldc
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 2=PX1kI
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 5dE@ePO[/9
EXEC (@TruncLog) KK%R3{
-- Wrap the log if necessary. 58@YWvAk
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 6RLYpQ$+
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) hY@rt,! 8
AND (@OriginalSize * 8 /1024) > @NewSize d/O~"d
BEGIN -- Outer loop. #DI%l`B
SELECT @Counter = 0 _Fz]QxO
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) l$~3_3+
BEGIN -- update bZ$;`F5})
INSERT DummyTrans VALUES ('Fill Log') i0y^b5@MOb
DELETE DummyTrans R"9^FQ13
SELECT @Counter = @Counter + 1 qQu}4Ye>
END {T^"`%[
EXEC (@TruncLog) ST#MCh-00
END j[Y$)HF
SELECT 'Final Size of ' + db_name() + ' LOG is ' + N:]71+
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ?W*{%my
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' W'BB FG
FROM sysfiles 2+7rLf`l
WHERE name = @LogicalFileName vjcG
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DROP TABLE DummyTrans G98P<cyD
SET NOCOUNT OFF I0
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8、说明:更改某个表 ?~vVSY
exec sp_changeobjectowner 'tablename','dbo' `5V=U9zdE
9、存储更改全部表 ZPieL&uV`
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch wE.CZ%f
@OldOwner as NVARCHAR(128), ,F,\bp }
@NewOwner as NVARCHAR(128) }Ss]/_t
AS 7S_rN!E1i*
DECLARE @Name as NVARCHAR(128) =z5'A|Wa=,
DECLARE @Owner as NVARCHAR(128) Kyz!YB
DECLARE @OwnerName as NVARCHAR(128) F3XB};
DECLARE curObject CURSOR FOR 6QwVgEnSf
select 'Name' = name, /A8ua=Kn
'Owner' = user_name(uid) WUwH W
from sysobjects (h}5*u%h
where user_name(uid)=@OldOwner g[]UM;D*
order by name ^usZ&9"@P
OPEN curObject EqN<""2
FETCH NEXT FROM curObject INTO @Name, @Owner 0h[pw
WHILE(@@FETCH_STATUS=0) `UC
BEGIN ;"}yVV/4
if @Owner=@OldOwner i'w8Li
begin \(ygdZ{R
set @OwnerName = @OldOwner + '.' + rtrim(@Name) iYqZBLf{S
exec sp_changeobjectowner @OwnerName, @NewOwner *Kpk1
end T<hS
-- select @name,@NewOwner,@OldOwner SXYH#p
FETCH NEXT FROM curObject INTO @Name, @Owner _2eRH@T
END B-oQ 9[~
close curObject \~sc6ho
deallocate curObject )w?DB@Tx
GO !e8OC9_x
10、SQL SERVER中直接循环写入数据 WR&>AOWAD
declare @i int q c(R
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set @i=1 #GDnV/0)
while @i<30 aC\O'KcH
begin @/MI
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insert into test (userid) values(@i) Zj+S"`P
set @i=@i+1 skd3E4
end E,~|-\b}h
小记存储过程中经常用到的本周,本月,本年函数 iKJ-$x_5
Dateadd(wk,datediff(wk,0,getdate()),-1) r{cefKJHg
Dateadd(wk,datediff(wk,0,getdate()),6) )\S3Q
Dateadd(mm,datediff(mm,0,getdate()),0) ;Y6XX_
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 5r&bk`
Dateadd(yy,datediff(yy,0,getdate()),0) ?QDHEC62
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) ans(^Up$
上面的SQL代码只是一个时间段 L}~"R/iWCT
Dateadd(wk,datediff(wk,0,getdate()),-1) iS p +~
Dateadd(wk,datediff(wk,0,getdate()),6) I_1(jaY
就是表示本周时间段. e=>:(^CS
下面的SQL的条件部分,就是查询时间段在本周范围内的: / [s TN.MG
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ~.Wlv;
而在存储过程中 "QKCZ8_C
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) &z;bX-"E
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) y%Q0*
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