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。
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一、基础 [}k|
1、说明:创建数据库 &l^n4
CREATE DATABASE database-name BR3mAF
2、说明:删除数据库 wixD\t59X
drop database dbname mTd<2Hy
3、说明:备份sql server #eEvF
--- 创建 备份数据的 device g~R/3cm4
USE master Uz>Yn&{y6
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 2]Fu
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--- 开始 备份 6Kht:WE
BACKUP DATABASE pubs TO testBack -Op@y2+c
4、说明:创建新表 ABiC9[Q0
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) -- S"w@
根据已有的表创建新表: !$E~\uT
A:create table tab_new like tab_old (使用旧表创建新表) wO.B~`y
B:create table tab_new as select col1,col2... from tab_old definition only 7 6*hc
5、说明:删除新表 m+$/DD^-zl
drop table tabname "'aqb~j^
6、说明:增加一个列 WB;J1TpM7
Alter table tabname add column col type Gc}0]!nrW9
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。 1Zq
7、说明:添加主键: Alter table tabname add primary key(col) $~hdm$
说明:删除主键: Alter table tabname drop primary key(col) E3tj/4:L
8、说明:创建索引:create [unique] index idxname on tabname(col....) '}zT1F*
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删除索引:drop index idxname *^6k[3VY
注:索引是不可更改的,想更改必须删除重新建。 nOuN|q=C
9、说明:创建视图:create view viewname as select statement TAAR'Jz S
删除视图:drop view viewname >C^/,/%v
10、说明:几个简单的基本的sql语句 0#
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选择:select * from table1 where 范围 lxOqs:b
插入:insert into table1(field1,field2) values(value1,value2) ?1DUNZ6
删除:delete from table1 where 范围 wz@/5c/u
更新:update table1 set field1=value1 where 范围 +9~ZA3DiP
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! !h/dZ`#
排序:select * from table1 order by field1,field2 [desc] %
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总数:select count as totalcount from table1 EFNdiv$wF
求和:select sum(field1) as sumvalue from table1 ,*w>z
平均:select avg(field1) as avgvalue from table1 _DrnL}9I7
最大:select max(field1) as maxvalue from table1 y3AL)
最小:select min(field1) as minvalue from table1 :+1bg&wQ
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11、说明:几个高级查询运算词 {"}+V`O{
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A: UNION 运算符 W9+h0A-
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。 y8D 8Y8B
B: EXCEPT 运算符 >+f'!*%7He
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。 F]Pul|.l
C: INTERSECT 运算符 lk~dgky@
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。 q"l>`KCG`
注:使用运算词的几个查询结果行必须是一致的。 HMQ'b(a'
12、说明:使用外连接 {'&8`d
A、left outer join: _32/WQF6
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。 KwQXA'
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 +}\29@{W
B:right outer join: i63?"
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。 vnF g%M!
C:full outer join: i!y\WaCp
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。 d^_itC;-,
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二、提升 xz="|HD);
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) BMe72
法一:select * into b from a where 1<>1 k\%,xf; x
法二:select top 0 * into b from a &7lk2Q\
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) {MA@A5
insert into b(a, b, c) select d,e,f from b; "&|lO|
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) *SXSF95
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 CARq^xI-
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. i{4'cdr?
4、说明:子查询(表名1:a 表名2:b) 3l.Nz@a*
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) #Xj;f^}/
5、说明:显示文章、提交人和最后回复时间 /S/tE
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b `7F@6n
6、说明:外连接查询(表名1:a 表名2:b) I"~xDa!
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c +0SW ?#%
7、说明:在线视图查询(表名1:a ) !;ZBL;qY9
select * from (SELECT a,b,c FROM a) T where t.a > 1; r$Yh)rpt:
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 NH<Y1t
select * from table1 where time between time1 and time2 ?@yank|
select a,b,c, from table1 where a not between 数值1 and 数值2 0LZ=`tI
9、说明:in 的使用方法 $)4GCP
select * from table1 where a [not] in ('值1','值2','值4','值6') )|MIWgfWN
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ;}n|,g>
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) j#4+-
11、说明:四表联查问题: ,K`E&hS
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 ..... ,,zd.9n
12、说明:日程安排提前五分钟提醒 (cu'
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 !7ph,/P$7
13、说明:一条sql 语句搞定数据库分页 C8!8u?k
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 f&+XPd %
14、说明:前10条记录 b*@&c9I;q
select top 10 * form table1 where 范围 0@JilGk1u
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) q+r `e
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ~r{\WZ.
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 J~M H_N
(select a from tableA ) except (select a from tableB) except (select a from tableC) |;X?">7NW
17、说明:随机取出10条数据 N:"M&EUM
select top 10 * from tablename order by newid() s0_-1VU
18、说明:随机选择记录 ab8oMi`z
select newid() m*Q[lr=
19、说明:删除重复记录 ?r^
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Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) hg$qbeUl
20、说明:列出数据库里所有的表名 ecM4]U
select name from sysobjects where type='U' "``W6W-(
21、说明:列出表里的所有的 3(cU)
select name from syscolumns where id=object_id('TableName') A%.J%[MVz
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。 Q:'qw#P/C
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 'Wo?%n
显示结果: ocb%&m;i
type vender pcs !hwzKm=%N
电脑 A 1 -G(3Y2
电脑 A 1 l{M;PaJ`}
光盘 B 2 )Ix-5084
光盘 A 2 tn(?nQN3
手机 B 3 D|u^8\'.
手机 C 3 PU,6h}
23、说明:初始化表table1 V[BY/<z)A
TRUNCATE TABLE table1 #rSasucr
24、说明:选择从10到15的记录 ^.ZSpc}<
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 0BbiQXU
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三、技巧 ;:#?~%7>
1、1=1,1=2的使用,在SQL语句组合时用的较多 oi33{#%t
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ^&f{beU9
如: *qeic e%E
if @strWhere !='' =DeHxPv}f
begin SH@
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere
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end .Um?5wG~i
else =!1-AR%.^
begin U.zRIhA]
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' _mIa8K;
end Uxj<x`<1x
我们可以直接写成 %J/fg<W1
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere "z{_hp{T^
2、收缩数据库 M~d+HE
--重建索引 a2(D!_dZR
DBCC REINDEX =UI,+P:
DBCC INDEXDEFRAG YN5OuKMUd'
--收缩数据和日志 @y;tk$e
DBCC SHRINKDB @=MZ6q
DBCC SHRINKFILE 6>LQGO
3、压缩数据库 Chb4VoE
dbcc shrinkdatabase(dbname) D@lAT#vA
4、转移数据库给新用户以已存在用户权限 npG+#z
exec sp_change_users_login 'update_one','newname','oldname' ]'1N_m]?
go 69<rsp(p
5、检查备份集 w|n?m
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' _>_ y@-b
6、修复数据库 0N3tsIm>
ALTER DATABASE [dvbbs] SET SINGLE_USER KOAz-h@6
GO XCqfAcNQ
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK =xlYQ}-(a
GO gR_b~^
ALTER DATABASE [dvbbs] SET MULTI_USER {%+3D,$)
GO 1Hk<_no5
7、日志清除 "z(fBnv
SET NOCOUNT ON 4?*"7t3
DECLARE @LogicalFileName sysname, i}$N&
@MaxMinutes INT, S#0|#Z5qD
@NewSize INT W O \lny!
USE tablename -- 要操作的数据库名 I%zo>s6
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 8G[Y9A(bmP
@MaxMinutes = 10, -- Limit on time allowed to wrap log. T0np<l]A
@NewSize = 1 -- 你想设定的日志文件的大小(M) %unK8z
-- Setup / initialize 1,;qXMhK`;
DECLARE @OriginalSize int H/v37%p7
SELECT @OriginalSize = size *C:q _/
FROM sysfiles O7<V@GL+
WHERE name = @LogicalFileName CSk
SELECT 'Original Size of ' + db_name() + ' LOG is ' + > {LJ#Dc6
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + m|?"
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' Z+"E*
FROM sysfiles 5x1jLPl'
WHERE name = @LogicalFileName 3/SqXu
CREATE TABLE DummyTrans v_1JH<GJ-
(DummyColumn char (8000) not null) L[[H\
DECLARE @Counter INT, ['N#aDh.?
@StartTime DATETIME, .n|3A3:
@TruncLog VARCHAR(255) WG[0$j
SELECT @StartTime = GETDATE(), C>K"ZJ
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' $Ln2O#
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Z5^,!6
EXEC (@TruncLog) lj}1'K@M
-- Wrap the log if necessary. bM3'm$34
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 2Nt]Nj`
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) *}WqYqOow
AND (@OriginalSize * 8 /1024) > @NewSize 7zkm
BEGIN -- Outer loop. aid)q&AcQ
SELECT @Counter = 0 G}hkr
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) B8#f^}8
BEGIN -- update v'Py[[R
INSERT DummyTrans VALUES ('Fill Log') ^&w'`-ra
DELETE DummyTrans ;uo|4?E:\(
SELECT @Counter = @Counter + 1 $}h_EI6hS
END Y8CYkJTAD-
EXEC (@TruncLog) O6/=/-?N=c
END +P6
SELECT 'Final Size of ' + db_name() + ' LOG is ' + VTX'f2\
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ,vY
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' u #QSa$P
FROM sysfiles
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WHERE name = @LogicalFileName 1MzB?[gx
DROP TABLE DummyTrans RkXLE"G'
SET NOCOUNT OFF ~(doy@0M
8、说明:更改某个表 "e};?|y
exec sp_changeobjectowner 'tablename','dbo' vR.6^q
9、存储更改全部表 %^@0tT
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Fb4S/_
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@OldOwner as NVARCHAR(128), -){^
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@NewOwner as NVARCHAR(128) oIR%{`3"I
AS 58gt*yVu
DECLARE @Name as NVARCHAR(128) vH\nL>r
DECLARE @Owner as NVARCHAR(128) O7_NXfh|
DECLARE @OwnerName as NVARCHAR(128) K]azUK7
DECLARE curObject CURSOR FOR }j<_JI
select 'Name' = name, sAAIyPJts
'Owner' = user_name(uid) ewlc ^`
from sysobjects Q^5 t]HKn
where user_name(uid)=@OldOwner xx2:5
order by name 9Qm{\
OPEN curObject '
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FETCH NEXT FROM curObject INTO @Name, @Owner cngPc]?N
WHILE(@@FETCH_STATUS=0) K>p:?w
BEGIN Uc;IPS
if @Owner=@OldOwner |P?B AWYeQ
begin $G([#N<
set @OwnerName = @OldOwner + '.' + rtrim(@Name) gmH0-W)=
exec sp_changeobjectowner @OwnerName, @NewOwner HE.Dl7{
end p.7p,CyB
-- select @name,@NewOwner,@OldOwner RPqn#B
FETCH NEXT FROM curObject INTO @Name, @Owner ZFw743G
END @[N~;>
close curObject si4=C
deallocate curObject $fpDABf
GO '`VO@a
10、SQL SERVER中直接循环写入数据 CMf~Yv
declare @i int Jx[e{o)o
set @i=1 Z`h_oK#y15
while @i<30 \}&w/.T
begin dufHd
insert into test (userid) values(@i) F,$$N>
set @i=@i+1 VTkT4C@I;Y
end F>{uB!!L4
小记存储过程中经常用到的本周,本月,本年函数 BP><G^
Dateadd(wk,datediff(wk,0,getdate()),-1) :<G+)hIK
Dateadd(wk,datediff(wk,0,getdate()),6) TgG)btQ
Dateadd(mm,datediff(mm,0,getdate()),0) ^O9m11
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) <}>-ip?
Dateadd(yy,datediff(yy,0,getdate()),0) ^*>no=A
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 2MrR|hLx
上面的SQL代码只是一个时间段 fC:\Gh5
Dateadd(wk,datediff(wk,0,getdate()),-1) f*f9:xUY
Dateadd(wk,datediff(wk,0,getdate()),6) UE](`|4H
就是表示本周时间段. *VAi!3Rx;
下面的SQL的条件部分,就是查询时间段在本周范围内的: "@bk$o=
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) b<MMli
而在存储过程中 os+wTUR^
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) (
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select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 8#3cmpx4