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。 N-
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一、基础 NDU,9A.P
1、说明:创建数据库
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CREATE DATABASE database-name #18H
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2、说明:删除数据库 xzy7I6X
drop database dbname ,Vt7Kiu
3、说明:备份sql server ' G-]>
--- 创建 备份数据的 device a|32Pn
USE master Rs{L
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' O qY8\>f-
--- 开始 备份 gCgMmD=AZ
BACKUP DATABASE pubs TO testBack 18Vtk"j
4、说明:创建新表 >c\'4M8Cz
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) OAR1u}
根据已有的表创建新表: _+%-WFS|
A:create table tab_new like tab_old (使用旧表创建新表) U#+S9jWe
B:create table tab_new as select col1,col2... from tab_old definition only E$34myOVf
5、说明:删除新表 0X`Qt[
drop table tabname ss% ahs
6、说明:增加一个列 jio1#&
Alter table tabname add column col type $B*E k>EK
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 RqXcL,,9
7、说明:添加主键: Alter table tabname add primary key(col) 1a| q&L`o
说明:删除主键: Alter table tabname drop primary key(col) 4<70mUnt
8、说明:创建索引:create [unique] index idxname on tabname(col....) 5P
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删除索引:drop index idxname IQoz8!guh:
注:索引是不可更改的,想更改必须删除重新建。 85m[^WGyh
9、说明:创建视图:create view viewname as select statement v@LK3S/!3
删除视图:drop view viewname >yg mE`g
10、说明:几个简单的基本的sql语句 9cWl/7;zXO
选择:select * from table1 where 范围 WcPDPu~/
插入:insert into table1(field1,field2) values(value1,value2) ,JN2q]QPP
删除:delete from table1 where 范围 g[44YrRD
更新:update table1 set field1=value1 where 范围 kG
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查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! kW4/0PD
排序:select * from table1 order by field1,field2 [desc] X(?.*m@+TB
总数:select count as totalcount from table1 d[w 'j/{
求和:select sum(field1) as sumvalue from table1 B1JdkL 3h
平均:select avg(field1) as avgvalue from table1 0lF[N.!\9
最大:select max(field1) as maxvalue from table1 5 r"`c
最小:select min(field1) as minvalue from table1 0MF[e3)a
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11、说明:几个高级查询运算词 #c'yAa
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A: UNION 运算符 j =r`[Bm
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 o
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B: EXCEPT 运算符 8V;@yzIha
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 {tV)+T
C: INTERSECT 运算符 %8>s :YG
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 4g b2$" !
注:使用运算词的几个查询结果行必须是一致的。 &kHp}\
12、说明:使用外连接 J i :2P*
A、left outer join:
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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。 V2,54YE
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 PSI5$Vna4p
B:right outer join: wRgmw
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右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 -f#0$Z/0
C:full outer join: "8&pT^
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。 7!#x-KR~5
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二、提升 ?5Wj y
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) yaMNt}y-q
法一:select * into b from a where 1<>1 wxkCmrV
法二:select top 0 * into b from a U>IllNd
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) !Sy._NE`z
insert into b(a, b, c) select d,e,f from b; _Buwz_[&
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) \acJ9N
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 U,LW(wueT
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. j5|_SQOmt
4、说明:子查询(表名1:a 表名2:b) LU l6^JU
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) $/Gvz)M
5、说明:显示文章、提交人和最后回复时间 VJDF/)X3$
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b >E|@3g
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6、说明:外连接查询(表名1:a 表名2:b) GRB/N1=
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c `$ZX]6G
7、说明:在线视图查询(表名1:a ) Y|_#yb
select * from (SELECT a,b,c FROM a) T where t.a > 1; MGfDxHg]
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 @HxEp;*NH"
select * from table1 where time between time1 and time2 6b~Zv$5^Y-
select a,b,c, from table1 where a not between 数值1 and 数值2 ]{{A/ j\
9、说明:in 的使用方法 N#Y%+1
select * from table1 where a [not] in ('值1','值2','值4','值6') h=.|!u
10、说明:两张关联表,删除主表中已经在副表中没有的信息 nW3-)Q89
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) yMq&9R9F
11、说明:四表联查问题: UQ:H3
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... ;o8C(5xE|
12、说明:日程安排提前五分钟提醒 ,=O`'l>K
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 AV Gu*
13、说明:一条sql 语句搞定数据库分页 Yc3\NqQM
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 ah1d0eP
14、说明:前10条记录 G+stt(k:
select top 10 * form table1 where 范围 mp!KPw08':
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) <{bQl
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) )XmV3.rI
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 AqB5B5}
(select a from tableA ) except (select a from tableB) except (select a from tableC) SG_^Rd9
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17、说明:随机取出10条数据 L{jJDd
select top 10 * from tablename order by newid() E0'+]"B
18、说明:随机选择记录 = I,O+^
select newid() VLC<ju!
19、说明:删除重复记录 9h>nP8
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) XAW$"^p
20、说明:列出数据库里所有的表名 >G$8\&]j
select name from sysobjects where type='U' Bw;sg;
21、说明:列出表里的所有的 -=iGl5P?
select name from syscolumns where id=object_id('TableName') "~(qp_AI
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 z8_m<uewz
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type lqn7$
显示结果: B8UtD
type vender pcs veAg?N<c
p
电脑 A 1 C8rD54A'M
电脑 A 1 $}_N379&
光盘 B 2 G#gUd'=M
光盘 A 2 lYmqFd~p
手机 B 3 (4cWq!ax<$
手机 C 3 ^q5~;_z|
23、说明:初始化表table1 3('=+d[}Vw
TRUNCATE TABLE table1 px %xoY
24、说明:选择从10到15的记录 26PUO$&b.
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc X1&Ug^
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三、技巧 59!yz'feF
1、1=1,1=2的使用,在SQL语句组合时用的较多 t~ruP',~\
"where 1=1" 是表示选择全部 "where 1=2"全部不选, $}V<Um
如: zI$^yk-vn
if @strWhere !='' &E0L7?l
begin 6E/>]3~!
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere wwrP7T+d
end dE19_KPm[j
else "[2CV!_
begin 0<_|K>5dS|
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' $3<,"&;Ecs
end 6w(Mb~[n
我们可以直接写成 +KgoL a
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ZUP\)[~
2、收缩数据库 M #'br<]
--重建索引 x;)bp7
DBCC REINDEX KY34Sc
DBCC INDEXDEFRAG ]E'BFon
--收缩数据和日志 XI:8_F;Q
DBCC SHRINKDB pd{W(M78g
DBCC SHRINKFILE =F'p#N0_2
3、压缩数据库 -1iKeyyA
dbcc shrinkdatabase(dbname) hTcy;zLLS
4、转移数据库给新用户以已存在用户权限 =+5z;3
exec sp_change_users_login 'update_one','newname','oldname'
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go QA>(}u\+
5、检查备份集 qzS 9ls>>
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' CF"$&+ s9
6、修复数据库 <6QG7i
ALTER DATABASE [dvbbs] SET SINGLE_USER j[l6&eX
GO xFxl9oM."
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK w}No ^.I*4
GO
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ALTER DATABASE [dvbbs] SET MULTI_USER =sy>_
GO Atsi}zTR\
7、日志清除 jXA!9_L7
SET NOCOUNT ON 6hDK;J J&
DECLARE @LogicalFileName sysname, b?9c\-}
@MaxMinutes INT, i{[=N9U5o
@NewSize INT y_EkW
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USE tablename -- 要操作的数据库名 uw!
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 JwCv(1$GM
@MaxMinutes = 10, -- Limit on time allowed to wrap log. u$ [R>l9
@NewSize = 1 -- 你想设定的日志文件的大小(M) +13h*
-- Setup / initialize MJNY#v3
DECLARE @OriginalSize int d]1%/$v^
SELECT @OriginalSize = size 2{;&c
FROM sysfiles R}Pw#*B
WHERE name = @LogicalFileName [M>Md-pj
SELECT 'Original Size of ' + db_name() + ' LOG is ' + :*bv(~FW
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 88}+.-3t$
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 7'u<)V
FROM sysfiles dv=y,q@W
WHERE name = @LogicalFileName 'f&o%5]
CREATE TABLE DummyTrans RrrW0<Ed
(DummyColumn char (8000) not null) r@N 0%JZZ
DECLARE @Counter INT, 5tPBTS<<"L
@StartTime DATETIME, K$OxeJP?F
@TruncLog VARCHAR(255) -c-af%xD
SELECT @StartTime = GETDATE(), . K`OEdr<
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' hY
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) [-o`^;
EXEC (@TruncLog) Gr9/@U+
-- Wrap the log if necessary.
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Fe
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AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) }L
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AND (@OriginalSize * 8 /1024) > @NewSize /2}o:vLj
BEGIN -- Outer loop. 1HQh%dZZ
SELECT @Counter = 0 ?#8',:
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) r~cmrLQa
BEGIN -- update
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INSERT DummyTrans VALUES ('Fill Log') &y`
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DELETE DummyTrans ' >(])Oq,
SELECT @Counter = @Counter + 1 HQHFD0hv
END 1'ne[@i^/
EXEC (@TruncLog) sX&.8
END d"3S[_U
SELECT 'Final Size of ' + db_name() + ' LOG is ' + tHNvb\MR$
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + jVP70c
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' w-2&6o<n-
FROM sysfiles QZy+`
WHERE name = @LogicalFileName |GuIp8~
DROP TABLE DummyTrans we'<Y
SET NOCOUNT OFF D|-^}I4
8、说明:更改某个表 x._IP,vRx^
exec sp_changeobjectowner 'tablename','dbo' Bz}Dgbb
9、存储更改全部表 fw>@:m_bK
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch !iKR~&UpAL
@OldOwner as NVARCHAR(128), DxjD/?R8
@NewOwner as NVARCHAR(128) JQ{g'cT
AS m87,N~DP
DECLARE @Name as NVARCHAR(128) k=w;jX&;`
DECLARE @Owner as NVARCHAR(128) mk>L:+
DECLARE @OwnerName as NVARCHAR(128) TU ]Ed*'&
DECLARE curObject CURSOR FOR 6#~"~WfPQ
select 'Name' = name, o`?0D)/O
'Owner' = user_name(uid) 49f- u
from sysobjects \s<7!NAE4
where user_name(uid)=@OldOwner :}d`$2Dz
order by name oI=7X*B9
OPEN curObject <S~_|Y*v
FETCH NEXT FROM curObject INTO @Name, @Owner IOA"O9;
WHILE(@@FETCH_STATUS=0) \PS{/XK
BEGIN M99#\0=/
if @Owner=@OldOwner i`o}*`//
begin =H*}{'#
set @OwnerName = @OldOwner + '.' + rtrim(@Name) shW$V93<
exec sp_changeobjectowner @OwnerName, @NewOwner U3r[ysf
end {MmHR
-- select @name,@NewOwner,@OldOwner `@GqD
FETCH NEXT FROM curObject INTO @Name, @Owner 9k\`3SE
END =! v.VF\;
close curObject ;t47cUm6j
deallocate curObject *S_e:^
GO |\ Nj
10、SQL SERVER中直接循环写入数据 /64jO?mp
declare @i int &tY3nr
set @i=1
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while @i<30 9 tZ)#@\
begin xsK{nM6g
insert into test (userid) values(@i) htc& !m
set @i=@i+1 $ q*kD#;mh
end -1Y9-nn[m
小记存储过程中经常用到的本周,本月,本年函数 gyH'92ck
Dateadd(wk,datediff(wk,0,getdate()),-1) /x.TF'Z*
Dateadd(wk,datediff(wk,0,getdate()),6) Q,Tet&in )
Dateadd(mm,datediff(mm,0,getdate()),0) ]2G5ng' @
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) <%eY>E
Dateadd(yy,datediff(yy,0,getdate()),0) ?]gZg[
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 4GJ1P2
上面的SQL代码只是一个时间段 EM/NT/
Dateadd(wk,datediff(wk,0,getdate()),-1) f@l 6]z{.L
Dateadd(wk,datediff(wk,0,getdate()),6) RAR0LKGX
就是表示本周时间段. 7t-j2 n`<
下面的SQL的条件部分,就是查询时间段在本周范围内的: /nXp5g^6(
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Wz$%o'OnC
而在存储过程中 @k~?h=o\b
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) ToNi<~
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) A(duUl~