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。 TuMZHB7h;
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一、基础 (I`<;
1、说明:创建数据库 hy"p8j7_
CREATE DATABASE database-name x2i`$iNhmP
2、说明:删除数据库 Fo"'[`
drop database dbname /C<} :R
3、说明:备份sql server jP@t!=
--- 创建 备份数据的 device iEFS>kL8e
USE master cNN_KA
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' jM@@N.
--- 开始 备份 AMgvk`<f
BACKUP DATABASE pubs TO testBack ;c~DBJg'|
4、说明:创建新表 }=3W(1cu-
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) p|Fhh\,*`X
根据已有的表创建新表: ]*S_fme
A:create table tab_new like tab_old (使用旧表创建新表) uuhvd h=
B:create table tab_new as select col1,col2... from tab_old definition only 8DrKq]&
5、说明:删除新表 Qe/=(P<
drop table tabname Hi{!<e2
6、说明:增加一个列 hG'2(Y!
Alter table tabname add column col type _Q;M$.[zyR
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。 8&f"")m
7、说明:添加主键: Alter table tabname add primary key(col) `|JQ)!Agx
说明:删除主键: Alter table tabname drop primary key(col) xcIZ'V
8、说明:创建索引:create [unique] index idxname on tabname(col....) nuv$B >
删除索引:drop index idxname 28+Sz>SP
注:索引是不可更改的,想更改必须删除重新建。 Z@i MG
9、说明:创建视图:create view viewname as select statement %@M/)"k
删除视图:drop view viewname fs]Zw mA^
10、说明:几个简单的基本的sql语句 h$zPQ""8
选择:select * from table1 where 范围
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插入:insert into table1(field1,field2) values(value1,value2) -p!KsU
删除:delete from table1 where 范围 Tf[-8H<
更新:update table1 set field1=value1 where 范围 M/sqOhg
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! d0Kg,HB
排序:select * from table1 order by field1,field2 [desc] a( {`<F
总数:select count as totalcount from table1 &<i>)Ss
求和:select sum(field1) as sumvalue from table1 L{CHAVkV
平均:select avg(field1) as avgvalue from table1 l 0b=;^6
最大:select max(field1) as maxvalue from table1 f<'&_*7,|t
最小:select min(field1) as minvalue from table1 N<Q}4%^c
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11、说明:几个高级查询运算词 vDOeBw=
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A: UNION 运算符 <ct {D|mm
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。 U14dQ=~b/
B: EXCEPT 运算符 $l[*Y
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 1@qb.9wZ6
C: INTERSECT 运算符 +Vf|YLbhJ
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 S(-=I!.G{
注:使用运算词的几个查询结果行必须是一致的。 iii$)4V
12、说明:使用外连接 C X'E+
A、left outer join: s9GPDfZ
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。 01q7n`o#zf
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 @%cJjZ5y
B:right outer join: s3kEux^
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。 gZ!(&u
C:full outer join: .y2<2eW
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。 }>XSp)"{l
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二、提升 (1}Ndo^;w
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ?h3Ow`1G
法一:select * into b from a where 1<>1 m<f{7]fi5
法二:select top 0 * into b from a sBu"$"]
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) hA\8&pI;
insert into b(a, b, c) select d,e,f from b; FW.dHvNX
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) Q#r 0DWo\
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 /eMZTh*1P
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. =nL*/
4、说明:子查询(表名1:a 表名2:b) %Z5k8
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) jh0$:6 `C
5、说明:显示文章、提交人和最后回复时间 nG*6ic
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
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6、说明:外连接查询(表名1:a 表名2:b) XP;&iZJ
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c #"yf^*wX
7、说明:在线视图查询(表名1:a ) M2EN(Y_k0
select * from (SELECT a,b,c FROM a) T where t.a > 1; ?Ru`ma\;
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 ^{K8uN7
select * from table1 where time between time1 and time2 aQmL=9
select a,b,c, from table1 where a not between 数值1 and 数值2 d=KOV;~);
9、说明:in 的使用方法 \j;uN#)28
select * from table1 where a [not] in ('值1','值2','值4','值6') cnPXvD^kY
10、说明:两张关联表,删除主表中已经在副表中没有的信息 (MIw$)#^
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) R39R$\
11、说明:四表联查问题: 5)oIPHXw
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 ..... lqCn5|S]
12、说明:日程安排提前五分钟提醒 g^4FzJ
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 rYS D-Kq
13、说明:一条sql 语句搞定数据库分页 *f#4S_ws`
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 q
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14、说明:前10条记录 0amz#VIB<u
select top 10 * form table1 where 范围 1DcarF
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.) k51s*U6=
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) O({_x@
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 O]g+z$2o
(select a from tableA ) except (select a from tableB) except (select a from tableC) -9*WQU9R
17、说明:随机取出10条数据 l9ihW^
select top 10 * from tablename order by newid() B;~agr
18、说明:随机选择记录 _Lb& 2PAG
select newid() *pD;AU
19、说明:删除重复记录 `^_:
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) @Kr)$F
20、说明:列出数据库里所有的表名 `k|nf9_
select name from sysobjects where type='U' `s_TY%&_}g
21、说明:列出表里的所有的 ^Q,/C8qeb
select name from syscolumns where id=object_id('TableName') ~+C#c,Nw
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}U
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 L K~,
显示结果: &P3vcB
type vender pcs <"+C<[n.
电脑 A 1 RM+E
电脑 A 1 KRZV9AJ
光盘 B 2 /nP=E
光盘 A 2 m'B6qy!}6
手机 B 3 MX0B$yc$
手机 C 3 WLl9>v^1
23、说明:初始化表table1 j1kc&(
TRUNCATE TABLE table1 `x VA]GR4c
24、说明:选择从10到15的记录 zNf5OItx
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc cj#q7
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三、技巧 :GYv9OG
1、1=1,1=2的使用,在SQL语句组合时用的较多 R4(8]oUW
"where 1=1" 是表示选择全部 "where 1=2"全部不选, /6c10}f
如: P[K=']c
if @strWhere !='' m^.C(}
begin %4Zy1{yKs_
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere jf/9]`Hf
end k#) .E X
else $IT9@}*{
begin wcf_5T
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' uP]o39b;V
end rfi`Bp
我们可以直接写成 A%2}?Ds
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere uCfp+
2、收缩数据库 sK?-@
--重建索引 j2M(W/_
DBCC REINDEX U9 *2< c
DBCC INDEXDEFRAG Ohag%<1#
--收缩数据和日志 hob$eWgr
DBCC SHRINKDB *^Y0}?]qT
DBCC SHRINKFILE se HbwO3 b
3、压缩数据库 iGMONJRO
dbcc shrinkdatabase(dbname) ZG<!^tj
4、转移数据库给新用户以已存在用户权限 yo,!u\^x
exec sp_change_users_login 'update_one','newname','oldname' r&sOM_BUF
go Q$L(fHkw
5、检查备份集 G9inNz*Cx
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' np^<HfYV
6、修复数据库 u(Sz$eV
ALTER DATABASE [dvbbs] SET SINGLE_USER a?~csP^?}
GO ONiI:Z>%
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK .boizW1+
GO %:?QE
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ALTER DATABASE [dvbbs] SET MULTI_USER #aX@mPm
GO SqF.DB~
7、日志清除 4"x;XVNM[
SET NOCOUNT ON \Egc5{
DECLARE @LogicalFileName sysname, f {Z%:H
@MaxMinutes INT, ja- ~`
@NewSize INT i%4k5[f.:
USE tablename -- 要操作的数据库名 i(iP}:3
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Ef!p:HBJ
@MaxMinutes = 10, -- Limit on time allowed to wrap log. gdE `UZ\
@NewSize = 1 -- 你想设定的日志文件的大小(M) >1G*ya)
-- Setup / initialize {taVAcb
DECLARE @OriginalSize int :$c:3~
SELECT @OriginalSize = size h)^A3;2F
FROM sysfiles DF|s,J`98
WHERE name = @LogicalFileName %H@76NvEz
SELECT 'Original Size of ' + db_name() + ' LOG is ' + zn1Rou]6
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + qU*&49X
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ]\,uF8gg)
FROM sysfiles `lezJ(Xm
WHERE name = @LogicalFileName 7O{O')o!
CREATE TABLE DummyTrans AWXpA1(
(DummyColumn char (8000) not null) ?lN8~Ze
DECLARE @Counter INT, xcvr D
@StartTime DATETIME, E0^%|Mh]b
@TruncLog VARCHAR(255) dHF$T33It
SELECT @StartTime = GETDATE(), 3,L3C9V'
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' qK
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) hUvuq,LH_
EXEC (@TruncLog) >-5Gt
-- Wrap the log if necessary. SuH.lCF-g
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ?VP!1O=J
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) !LOors za
AND (@OriginalSize * 8 /1024) > @NewSize
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BEGIN -- Outer loop. DE\bYxJ
SELECT @Counter = 0 uE#,c\[8
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) g+ 1=5g
BEGIN -- update /:{_| P\
INSERT DummyTrans VALUES ('Fill Log') ~uR6z//%
DELETE DummyTrans <-B"|u
SELECT @Counter = @Counter + 1 ]Bd3d%
END @@3,+7%1
EXEC (@TruncLog) "=\_++
END Wo9psv7.
SELECT 'Final Size of ' + db_name() + ' LOG is ' + F0'A/T'ht
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + fb.\V]K
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' F:o#
FROM sysfiles I,4-
WHERE name = @LogicalFileName X0Z-1bs
DROP TABLE DummyTrans -F+P;S
SET NOCOUNT OFF =ch
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8、说明:更改某个表 WCmNibj
exec sp_changeobjectowner 'tablename','dbo' m_!vIUOz
9、存储更改全部表 4!~
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Qj<{oZp&
@OldOwner as NVARCHAR(128), YG 5Z8@kH
@NewOwner as NVARCHAR(128) lAn+gDP
AS Q|=
Q]$d
DECLARE @Name as NVARCHAR(128) DxKfWb5 R
DECLARE @Owner as NVARCHAR(128) w-H%B`/
DECLARE @OwnerName as NVARCHAR(128) LX\*4[0%K
DECLARE curObject CURSOR FOR C7 ]DJn
select 'Name' = name, d9-mWz(V+
'Owner' = user_name(uid)
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from sysobjects k/_8!^:'
where user_name(uid)=@OldOwner FL#g9U>
order by name Uy59zB2|=
OPEN curObject e4=FU&RpNH
FETCH NEXT FROM curObject INTO @Name, @Owner ^/C$L8#
WHILE(@@FETCH_STATUS=0) 1 73<x){
BEGIN Go\} A:|s
if @Owner=@OldOwner Z#F,y)YiO
begin $TA6S+
set @OwnerName = @OldOwner + '.' + rtrim(@Name) gJ3OK !/
exec sp_changeobjectowner @OwnerName, @NewOwner 8S1P&+iKs
end RHx+HBZ
-- select @name,@NewOwner,@OldOwner ~i }+P71
FETCH NEXT FROM curObject INTO @Name, @Owner !<=%;+
END EN-H4F
close curObject ?#*
deallocate curObject v= *Bb3dt
GO /}nrF4S
10、SQL SERVER中直接循环写入数据 _D>as\dP
declare @i int 88#qu.
set @i=1 UROj9COv
while @i<30 ?H[5O+P[
begin ^0Q=#p
insert into test (userid) values(@i) Q\27\2
set @i=@i+1 EO].qN-8
end X$- boe?
小记存储过程中经常用到的本周,本月,本年函数 %]chL.s
Dateadd(wk,datediff(wk,0,getdate()),-1) 2fzKdkJhe
Dateadd(wk,datediff(wk,0,getdate()),6) %R5Com
Dateadd(mm,datediff(mm,0,getdate()),0) ," C[Qg(
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) y^X\^Kq
Dateadd(yy,datediff(yy,0,getdate()),0) X%a;i6pq
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) b$?Xn {Y
上面的SQL代码只是一个时间段 WO.0K5nfk
Dateadd(wk,datediff(wk,0,getdate()),-1) ;v,9v;T
Dateadd(wk,datediff(wk,0,getdate()),6) \7,MZt
就是表示本周时间段. %wt2F-u
下面的SQL的条件部分,就是查询时间段在本周范围内的: `y^zM/Ib
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) _oJ2]f6KX
而在存储过程中 X`fhln9N
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 5@ bc(H
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) [;?"R-V"z