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。 .SER,],P
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一、基础 <r t$~}
1、说明:创建数据库 +qC[X~\
CREATE DATABASE database-name ]S[?tn
2、说明:删除数据库 -D'XxOI
drop database dbname Bdb}4X rL
3、说明:备份sql server iRlZWgj4^
--- 创建 备份数据的 device Dm5 Uy^F}
USE master Y7r;}^+WY
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' QDJ
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--- 开始 备份 !|H,g wqU
BACKUP DATABASE pubs TO testBack =&$z
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4、说明:创建新表 c3g`k"3*`
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) Abt<23$h
根据已有的表创建新表: %'2.9dB
A:create table tab_new like tab_old (使用旧表创建新表) 7H< IO`
B:create table tab_new as select col1,col2... from tab_old definition only *URT-+'
5、说明:删除新表 S_Wq`I@b
drop table tabname "V26\
6、说明:增加一个列 p'2IlQ\
Alter table tabname add column col type 9*ZlNZ
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 >$L7J=Em
7、说明:添加主键: Alter table tabname add primary key(col) igk<]AwxS
说明:删除主键: Alter table tabname drop primary key(col) mY4pvpZw8
8、说明:创建索引:create [unique] index idxname on tabname(col....) R)Arr77
删除索引:drop index idxname #O\as~-
注:索引是不可更改的,想更改必须删除重新建。 $Vq5U9-
9、说明:创建视图:create view viewname as select statement xn503,5G*7
删除视图:drop view viewname prz COw
10、说明:几个简单的基本的sql语句 :ZIa
选择:select * from table1 where 范围 pa+'0Y]71
插入:insert into table1(field1,field2) values(value1,value2) -kMw[Y
删除:delete from table1 where 范围 ?{B5gaU9F
更新:update table1 set field1=value1 where 范围 p8%qU>~+4
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! n-" (~
排序:select * from table1 order by field1,field2 [desc] nk%v|ZxoFv
总数:select count as totalcount from table1 52tc|j6~#
求和:select sum(field1) as sumvalue from table1 0
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平均:select avg(field1) as avgvalue from table1 g}D)MlXRq
最大:select max(field1) as maxvalue from table1 u5k{.&
最小:select min(field1) as minvalue from table1 hoqZb<:
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11、说明:几个高级查询运算词 D~ Y6%9
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A: UNION 运算符 BL16?&RK
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 Nb&j?./
B: EXCEPT 运算符 3U{
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EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 Mp|Jt
C: INTERSECT 运算符 cE
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INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 <Q9l'u]3$c
注:使用运算词的几个查询结果行必须是一致的。 aX;>XL4
12、说明:使用外连接 NknS:r&2
A、left outer join: g&xj(SMj-$
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。 2MRd
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 OVi<d
B:right outer join: fc*>ky.v
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。 1 #,4P1"
C:full outer join: jL\j$'KC
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。 OA&'T*)-A6
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二、提升 )tI^2p{
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) &<98nT
法一:select * into b from a where 1<>1 H}F
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法二:select top 0 * into b from a ^:{8z;w!(
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) xX%ppD7
insert into b(a, b, c) select d,e,f from b; \(i'i C
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) l[$GOLeS
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 lfHN_fE>Mq
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. HfVHjF)
4、说明:子查询(表名1:a 表名2:b) ?uSoJM`wa!
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) K'Ywv@
5、说明:显示文章、提交人和最后回复时间 2j%=o?me^p
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ?K[Y"*y2
6、说明:外连接查询(表名1:a 表名2:b) j9>[^t3U
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Unb2D4&'
7、说明:在线视图查询(表名1:a ) KSchgon0V
select * from (SELECT a,b,c FROM a) T where t.a > 1; f%o[eW#
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 HRyFjAR\?
select * from table1 where time between time1 and time2 ^Qx?)(@
select a,b,c, from table1 where a not between 数值1 and 数值2 U 3a2wK
9、说明:in 的使用方法 UXBWCo;-
select * from table1 where a [not] in ('值1','值2','值4','值6') 1,+<|c)T?
10、说明:两张关联表,删除主表中已经在副表中没有的信息 g D6S%O
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) sWr;%<K
11、说明:四表联查问题: p6<JpW5@_
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 ..... (NLw#)?
12、说明:日程安排提前五分钟提醒 #("M4}~
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ,yGbMOV
13、说明:一条sql 语句搞定数据库分页 YQN:&Cls
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 E,6|-V;?
14、说明:前10条记录 O]PM L`
select top 10 * form table1 where 范围 _,L_H[FN
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.) &6vaLx
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) w/*G!o-<
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 toPbFU'
(select a from tableA ) except (select a from tableB) except (select a from tableC) 7?whxi Qs
17、说明:随机取出10条数据 -4Hb]#*2
select top 10 * from tablename order by newid() ,6{z
18、说明:随机选择记录 MWv@]P_0p!
select newid() 7(+4^
19、说明:删除重复记录 'Eur[~k
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ev;&n@k_I
20、说明:列出数据库里所有的表名 `#ruZM066
select name from sysobjects where type='U' D ;> 7y}\
21、说明:列出表里的所有的 v@%4i~N
select name from syscolumns where id=object_id('TableName') ~x,_A>a
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。 6AJk6W^Z
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 bs"J]">(N
显示结果: xkDK5&V
type vender pcs kku<0<(N
电脑 A 1 JI.=y5I
电脑 A 1 _s5^\~ao
光盘 B 2 H}kZ;8
光盘 A 2 [ *Dj:A)V^
手机 B 3 C~pas~
手机 C 3 @bA5uY!
23、说明:初始化表table1 $@'BB=i
TRUNCATE TABLE table1 X3}eq|r9
24、说明:选择从10到15的记录 \:J=tAC
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc c},pu[nL
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三、技巧 HQP.7.w7 5
1、1=1,1=2的使用,在SQL语句组合时用的较多 We{@0K/O
"where 1=1" 是表示选择全部 "where 1=2"全部不选, MMFg{8
如: 0vjCSU-X
if @strWhere !='' <rE>?zvm
begin j$q5m 24L
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere YYn8!FIe
end &NBH'Rt
else BEaF-*?A
begin yIKpyyC9H
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' _!o8s%9be
end %N-aLw\
我们可以直接写成 Z>`\$1CI
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere )7*'r@
2、收缩数据库 cK1^jH<|
--重建索引 $~6MR_Yq
DBCC REINDEX 6HK1?
DBCC INDEXDEFRAG <{cY2cx~3
--收缩数据和日志 6
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DBCC SHRINKDB xw9ZRu<z
DBCC SHRINKFILE F~6]II
3、压缩数据库 ,5$G0
dbcc shrinkdatabase(dbname) o>8~rtl
4、转移数据库给新用户以已存在用户权限 ;<garDf
exec sp_change_users_login 'update_one','newname','oldname' R278 ^E
go T]wI)
5、检查备份集 1M&Lb.J6
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Ge`7`D>L
6、修复数据库 G~1;_'
ALTER DATABASE [dvbbs] SET SINGLE_USER !-OZ/^l|O`
GO lq:q0>vyI
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK \B4H0f
GO id:,\iJ
ALTER DATABASE [dvbbs] SET MULTI_USER yo#r^iAr
GO 3l?|+sU>O
7、日志清除 AT1cN1:4?
SET NOCOUNT ON SvSO?H!-
DECLARE @LogicalFileName sysname, o08g]a
@MaxMinutes INT, D@La-K*5
@NewSize INT veq3t$sj
USE tablename -- 要操作的数据库名 A8&@Vxdz
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ! :]_-DX
@MaxMinutes = 10, -- Limit on time allowed to wrap log. #$BFTlm|
@NewSize = 1 -- 你想设定的日志文件的大小(M) }eVDe(7_
-- Setup / initialize 72Bc0Wg
DECLARE @OriginalSize int et+lL"&
SELECT @OriginalSize = size #4m5I="
FROM sysfiles VF2,(f-*
WHERE name = @LogicalFileName IRQtA
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SELECT 'Original Size of ' + db_name() + ' LOG is ' + h7+"*fN
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + /= ;,lC
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' [`GSc6j
FROM sysfiles PFX,X
WHERE name = @LogicalFileName r[V%DU$dj
CREATE TABLE DummyTrans nZB~l=
(DummyColumn char (8000) not null) l{7}3Am6
DECLARE @Counter INT, hn2:@^=f
@StartTime DATETIME, %J1'>nI!q
@TruncLog VARCHAR(255) @LI;q
SELECT @StartTime = GETDATE(), 6c]4(%8
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' @;eH~3P
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 6 EqN>.
EXEC (@TruncLog) G06;x
-- Wrap the log if necessary. F\N0<o
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 7#C$}1XJ1
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 2B$dT=G
AND (@OriginalSize * 8 /1024) > @NewSize }SWfP5D@
BEGIN -- Outer loop. 9!jF$
SELECT @Counter = 0 I+
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WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) %EU_OS(u.{
BEGIN -- update F8?,}5j
INSERT DummyTrans VALUES ('Fill Log') f0g/`j@Up
DELETE DummyTrans FBl,Mky
SELECT @Counter = @Counter + 1 W\Pd:t
END Z~SAlhT
EXEC (@TruncLog) #Q=73~
END *N$XQ{o
SELECT 'Final Size of ' + db_name() + ' LOG is ' + u;9iuc`*
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + fh`Y2s|:7R
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Mk#r_:[BS
FROM sysfiles Mi.2
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WHERE name = @LogicalFileName "}_J"%
DROP TABLE DummyTrans
= "]r{
SET NOCOUNT OFF 1L::Qu%E
8、说明:更改某个表 :.AC%'S
exec sp_changeobjectowner 'tablename','dbo' (DvPdOT+3
9、存储更改全部表 WILa8"M
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch |5(un#
@OldOwner as NVARCHAR(128), o+hp#e
@NewOwner as NVARCHAR(128) %6(\Ki6I
AS =k<b* 8
DECLARE @Name as NVARCHAR(128) **m8 HD
DECLARE @Owner as NVARCHAR(128) 7Z2D}O+
DECLARE @OwnerName as NVARCHAR(128) w
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DECLARE curObject CURSOR FOR B)7 :*Kj
select 'Name' = name, h:bx0:O"
'Owner' = user_name(uid) s;P _LaIp)
from sysobjects }BS
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where user_name(uid)=@OldOwner H%m^8yW1
order by name X$==J St
OPEN curObject a"P &
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FETCH NEXT FROM curObject INTO @Name, @Owner Fw[1Aa#
WHILE(@@FETCH_STATUS=0) 6?}|@y^fb
BEGIN ,2!7iX
if @Owner=@OldOwner 1.p?1"4\u
begin BsXF'x<U*
set @OwnerName = @OldOwner + '.' + rtrim(@Name) P4"BX*x
exec sp_changeobjectowner @OwnerName, @NewOwner c),UO^EqV
end pRjEuOc
-- select @name,@NewOwner,@OldOwner w;@v#<q6
FETCH NEXT FROM curObject INTO @Name, @Owner by9UwM=gp
END J37vA zK%
close curObject G0:<#?<5
deallocate curObject w@2NXcmw
GO w +UBXW
10、SQL SERVER中直接循环写入数据 4;~xRg;u&*
declare @i int ww
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set @i=1 #vK99S2
while @i<30 "T /$K
begin w,6gnO
insert into test (userid) values(@i) Zu#^a|PE*
set @i=@i+1 ax _v+v %
end dn~k_J=p
小记存储过程中经常用到的本周,本月,本年函数 W"/,<xHuh
Dateadd(wk,datediff(wk,0,getdate()),-1) 7KC2%s#7
Dateadd(wk,datediff(wk,0,getdate()),6) .gNJY7`b
Dateadd(mm,datediff(mm,0,getdate()),0) HRahBTd(z
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) BpFXe7
Dateadd(yy,datediff(yy,0,getdate()),0) Yc[vH=gV}
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) p&(z'd
上面的SQL代码只是一个时间段 mtFC H
Dateadd(wk,datediff(wk,0,getdate()),-1) +tkm,>s
Dateadd(wk,datediff(wk,0,getdate()),6) #?M[Q:
就是表示本周时间段. I7XM2xM
下面的SQL的条件部分,就是查询时间段在本周范围内的: Y]&2E/oc
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) A\/DAVnI
而在存储过程中 IwXQbJ3v_
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) )q!dMZ(
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) r^s$U,e#~