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。 j g8fU
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一、基础 +
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1、说明:创建数据库
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CREATE DATABASE database-name `w.n]TR
2、说明:删除数据库 $a
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drop database dbname JM x>][xD
3、说明:备份sql server pe] A5\4c
--- 创建 备份数据的 device n1ly
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USE master G9xmmc
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' '>cKH$nVC}
--- 开始 备份 95A1:A^t
BACKUP DATABASE pubs TO testBack Xq_5Qv
4、说明:创建新表 2jR r,Nl
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) /OLFcxEWh
根据已有的表创建新表: =cm~vDl[
A:create table tab_new like tab_old (使用旧表创建新表) lku[dQdk
B:create table tab_new as select col1,col2... from tab_old definition only =g9*UzA"O
5、说明:删除新表 |=`~-i2W
drop table tabname /aZ+T5O
6、说明:增加一个列 aMWmLpv4'
Alter table tabname add column col type zO ).T
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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。 nD`w/0hT<
7、说明:添加主键: Alter table tabname add primary key(col) 9Iwe2lu
说明:删除主键: Alter table tabname drop primary key(col) G6/p1xy>o:
8、说明:创建索引:create [unique] index idxname on tabname(col....) BK)$'AqO
删除索引:drop index idxname g;qx">xJ`o
注:索引是不可更改的,想更改必须删除重新建。 n
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9、说明:创建视图:create view viewname as select statement ==3dEJS
删除视图:drop view viewname Xejo_SV&?
10、说明:几个简单的基本的sql语句 >qS9PX
选择:select * from table1 where 范围 8Kg n"M3
插入:insert into table1(field1,field2) values(value1,value2) j|U#)v/
删除:delete from table1 where 范围 r+":' /[x
更新:update table1 set field1=value1 where 范围 rH_\d?b
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! }1Gv)l7
排序:select * from table1 order by field1,field2 [desc] Cd,jDPrw
总数:select count as totalcount from table1 FbS|~Rp~
求和:select sum(field1) as sumvalue from table1 +
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平均:select avg(field1) as avgvalue from table1 'ig&$fz b
最大:select max(field1) as maxvalue from table1 w<Wf?a G
最小:select min(field1) as minvalue from table1 /fZeWU0W
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11、说明:几个高级查询运算词 mZSD(
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A: UNION 运算符 w80oXXs[#
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。 cq}EZ@ .
B: EXCEPT 运算符 `A w^H!
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。 .
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C: INTERSECT 运算符 =Je[c,&j$?
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。 tnH2sHby
注:使用运算词的几个查询结果行必须是一致的。 Al}6q{E9+8
12、说明:使用外连接 `UD/}j@
A、left outer join: _ FpTFfB
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。 ad*m%9Y1Q
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 wSa)*]%
B:right outer join: &dM.
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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。 A#.edVj.g4
C:full outer join: ,K)_OVB
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。 w_.F'
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二、提升 pT=JP> nd^
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) NW]Lj>0Y
法一:select * into b from a where 1<>1 W42iu"@
法二:select top 0 * into b from a S2HcG
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) (;T^8mI2
insert into b(a, b, c) select d,e,f from b; :r{<zd>;
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) /]K^
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insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 F*IzQ(#HW
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. >AVVEv18
4、说明:子查询(表名1:a 表名2:b) vdAr|4^qB
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) #|L8tuWW
5、说明:显示文章、提交人和最后回复时间 ,:%CB"J
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b [pbo4e,4O
6、说明:外连接查询(表名1:a 表名2:b) RRmz"j>
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ULs\+U
7、说明:在线视图查询(表名1:a ) ;_c;0)
select * from (SELECT a,b,c FROM a) T where t.a > 1; 1oR7iD^
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 Zq+v6fk_Mn
select * from table1 where time between time1 and time2 X{5vXT\/y
select a,b,c, from table1 where a not between 数值1 and 数值2 S\:P-&dC
9、说明:in 的使用方法 ZP@
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select * from table1 where a [not] in ('值1','值2','值4','值6') wPQH(~k:
10、说明:两张关联表,删除主表中已经在副表中没有的信息 cG[l!Z
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) .~~nUu+M
11、说明:四表联查问题: 8&GBV_`I
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 ..... tXNm$Cq.|
12、说明:日程安排提前五分钟提醒 !%CWZZ 6u
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 g;pcZ9o
13、说明:一条sql 语句搞定数据库分页 s'!Cp=xQF"
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 J1( 9QN[w
14、说明:前10条记录 RIlwdt
select top 10 * form table1 where 范围 ]~9tYn
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.) /rK}?U
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) (?n=33}Ci
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 Q_"]+i]s@
(select a from tableA ) except (select a from tableB) except (select a from tableC) ck:T,F{}
17、说明:随机取出10条数据 [%q@]\U$s
select top 10 * from tablename order by newid() *=8JIs A>!
18、说明:随机选择记录 n6wV.?8
select newid() {m4b(t`xw
19、说明:删除重复记录 a L} %2
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) J"!vu.[
20、说明:列出数据库里所有的表名 '~5LY!H(pT
select name from sysobjects where type='U' x-$&g*<
21、说明:列出表里的所有的 VJeu8ZJ.
select name from syscolumns where id=object_id('TableName') 94h]~GqNi
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。 &v56#lG
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 [4YTDEv%
显示结果: XW[j!`nlk
type vender pcs `F-/QX[:
电脑 A 1 s2h@~y
电脑 A 1 Rw"sJ) /
光盘 B 2 CS2Bo
光盘 A 2 v\c>b:AofD
手机 B 3 EAT"pxP
手机 C 3 eWCb73
23、说明:初始化表table1 `#rL*;\uV
TRUNCATE TABLE table1 <CS(c|7
24、说明:选择从10到15的记录 l{5IUuUi
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc "sS}N%!
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三、技巧 &-;4.op
1、1=1,1=2的使用,在SQL语句组合时用的较多 !\-{D$E?H
"where 1=1" 是表示选择全部 "where 1=2"全部不选, (ceNO4"cZ
如: t)~"4]{*}D
if @strWhere !='' @@R7p
begin BBaQ}{F8>2
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere *1uKr9
end o*-)Tq8GHE
else U_M$#i{_
begin Z?6%;n^ 54
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' @3) (BpFe
end qyZ"
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我们可以直接写成 J1,9kCO
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere (/z_Q{"N
2、收缩数据库 E%yNa]\P
--重建索引 o*b] p-
DBCC REINDEX *QpMF/<?
DBCC INDEXDEFRAG xe]y]
--收缩数据和日志 +NeOSQSj
DBCC SHRINKDB (uXL^oja
DBCC SHRINKFILE VU#`oJ:{
3、压缩数据库 3-[q4R
dbcc shrinkdatabase(dbname) 7r7YNn/?
4、转移数据库给新用户以已存在用户权限 'H3^e}
exec sp_change_users_login 'update_one','newname','oldname' T5R-B=YWu
go ;ic3).H
5、检查备份集 v_<rNc,z-s
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 6^V=?~a&z
6、修复数据库 pM+ AjPr
ALTER DATABASE [dvbbs] SET SINGLE_USER 2a-w%
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GO |nc@"OJ
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK %>yG+Od5Z
GO IshKH-
ALTER DATABASE [dvbbs] SET MULTI_USER 'KP@W9j
GO wrc,b{{[iM
7、日志清除 ^&B@Uw5{
SET NOCOUNT ON i5en*)O8
DECLARE @LogicalFileName sysname, oQLq&zRH`f
@MaxMinutes INT, xu>9(,l
@NewSize INT V_R@o3kv;
USE tablename -- 要操作的数据库名 xR-%L
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 F0pir(n-
@MaxMinutes = 10, -- Limit on time allowed to wrap log. hcgMZT!<5
@NewSize = 1 -- 你想设定的日志文件的大小(M) 9%k2'iV7
-- Setup / initialize ?8I?'\F;
DECLARE @OriginalSize int
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SELECT @OriginalSize = size 8LyD7P1\
FROM sysfiles R]vV*
WHERE name = @LogicalFileName cm&nd'A't
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ; ^*}#Xd
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + O(#)m>A
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' &T+atL `N
FROM sysfiles cbNTj$'b2u
WHERE name = @LogicalFileName F5LuSy+v
CREATE TABLE DummyTrans fX(3H1$"
(DummyColumn char (8000) not null) {'NZ.
DECLARE @Counter INT, AV:hBoO
@StartTime DATETIME, O_2pIbh
@TruncLog VARCHAR(255) BHIRHmM<Y
SELECT @StartTime = GETDATE(), X@'uy<tI-
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' (lXGmx8
DBCC SHRINKFILE (@LogicalFileName, @NewSize) A^nvp!_
EXEC (@TruncLog) t=(!\:[D
-- Wrap the log if necessary. cpe+XvBuK
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Mz9r5
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) dV*]f$wQ
AND (@OriginalSize * 8 /1024) > @NewSize Gk.
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BEGIN -- Outer loop. |!1Y*|Q%s
SELECT @Counter = 0 (jnzT=y
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) &x=.$76
BEGIN -- update F<ZYh
INSERT DummyTrans VALUES ('Fill Log') =qoWCmg"&
DELETE DummyTrans zbXI%
SELECT @Counter = @Counter + 1 uX"H4lO~
END }'5MK
EXEC (@TruncLog) dWM'fg
END *!4Z#Y
SELECT 'Final Size of ' + db_name() + ' LOG is ' + szb_*)k
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + i#&z2h-b
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' >] qc-{>&
FROM sysfiles _mzW'~9wN
WHERE name = @LogicalFileName O#n8=B4
DROP TABLE DummyTrans Hta y-PB }
SET NOCOUNT OFF jk"`Z<j~
8、说明:更改某个表 45=bGf#
exec sp_changeobjectowner 'tablename','dbo' Qn^'
9、存储更改全部表 dl.N.P7}4
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch dah[:rP,n{
@OldOwner as NVARCHAR(128), b1?#81
@NewOwner as NVARCHAR(128) teOe#*
AS }wWKFX
DECLARE @Name as NVARCHAR(128) QgrpBG
DECLARE @Owner as NVARCHAR(128) \n" {qfn`r
DECLARE @OwnerName as NVARCHAR(128) QsGiclU
DECLARE curObject CURSOR FOR Rh3eLt~|(
select 'Name' = name, Eou~P h*t
'Owner' = user_name(uid) d4m=0G`
from sysobjects .0p0_f=
where user_name(uid)=@OldOwner ZWii)0'PV
order by name R]Vt Y7}i,
OPEN curObject G
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FETCH NEXT FROM curObject INTO @Name, @Owner ~Xw"}S5
WHILE(@@FETCH_STATUS=0) !ds"9w
BEGIN 5(Cl1Yse=r
if @Owner=@OldOwner 8a&:6Zuo
begin Zvhsyz|
set @OwnerName = @OldOwner + '.' + rtrim(@Name) fs|)l$Rd
exec sp_changeobjectowner @OwnerName, @NewOwner UN7EF/!Zz
end VGLaN%|
-- select @name,@NewOwner,@OldOwner !*/*8re
FETCH NEXT FROM curObject INTO @Name, @Owner @M<|:Z %.@
END yTyj'-4
close curObject x9NEFtqjm
deallocate curObject ".f ;+wH
GO xpNH?#&
10、SQL SERVER中直接循环写入数据 iF*:d
declare @i int Om \o#{D
set @i=1 -Q2, "
while @i<30 cy*?&~;
begin *EI6dD"
insert into test (userid) values(@i) 5VRYO"D:
set @i=@i+1 /xG*,YL/q
end sJ\BF
小记存储过程中经常用到的本周,本月,本年函数 HPpR.
Dateadd(wk,datediff(wk,0,getdate()),-1) 7t3X)Ah
Dateadd(wk,datediff(wk,0,getdate()),6) |VKK#J/
Dateadd(mm,datediff(mm,0,getdate()),0) #w;v0&p
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) rI{=WPI&WU
Dateadd(yy,datediff(yy,0,getdate()),0) ,t}vz 7
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) -_ I_W&
上面的SQL代码只是一个时间段 -)s qc
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Dateadd(wk,datediff(wk,0,getdate()),-1) KTK <gV9:
Dateadd(wk,datediff(wk,0,getdate()),6) J%8(kWQ|
就是表示本周时间段. Us%T;gW
下面的SQL的条件部分,就是查询时间段在本周范围内的: o-;E>N7t
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) K7$x<5 +)
而在存储过程中 yZd +^QN
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) zFfoqb#*g
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) R= a|Blp