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。 #D8Z~U,-
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一、基础 g%()8QxE1
1、说明:创建数据库 l(X8 cHAi
CREATE DATABASE database-name BxR%\
2、说明:删除数据库 z"/Mva3|
drop database dbname 4u}"ng
3、说明:备份sql server |GPR3%9
--- 创建 备份数据的 device 27mGX\T
USE master !O=?n<Ex"
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' =@%;6`AVcp
--- 开始 备份 B&^WRM;7t
BACKUP DATABASE pubs TO testBack ke.{wh\0
4、说明:创建新表 VrL==aTYXs
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) .XPcH(q
根据已有的表创建新表: e.pm`%5bO
A:create table tab_new like tab_old (使用旧表创建新表) 1 o<l;:
B:create table tab_new as select col1,col2... from tab_old definition only !:
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5、说明:删除新表 c)H(w
drop table tabname 4dy2m!
6、说明:增加一个列 -dX{ R_*
Alter table tabname add column col type |Z%I3-z_DS
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。 Xk#"rM< Y
7、说明:添加主键: Alter table tabname add primary key(col) @\-i3EhR
说明:删除主键: Alter table tabname drop primary key(col) J6x#c`Y
8、说明:创建索引:create [unique] index idxname on tabname(col....) yn&AMq
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删除索引:drop index idxname Z4YQ5O5
注:索引是不可更改的,想更改必须删除重新建。 >~O36q^w
9、说明:创建视图:create view viewname as select statement hw[ jVx
删除视图:drop view viewname +$]eA'Bh@
10、说明:几个简单的基本的sql语句 TBq;#+1W
选择:select * from table1 where 范围 |n9~2R
插入:insert into table1(field1,field2) values(value1,value2) I5RV:e5b
删除:delete from table1 where 范围 9o-fI@9
更新:update table1 set field1=value1 where 范围 !'uLV#YEZ
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! >r Nff!Ow
排序:select * from table1 order by field1,field2 [desc] Y|ONCc
总数:select count as totalcount from table1 diXb8L7B;
求和:select sum(field1) as sumvalue from table1 mNcoR^(VN
平均:select avg(field1) as avgvalue from table1 ?Y6MC:l<
最大:select max(field1) as maxvalue from table1 om 3$=
最小:select min(field1) as minvalue from table1 -rE_ pV;
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11、说明:几个高级查询运算词 ml7nt0{
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A: UNION 运算符 =[Lo9Sg
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。 $lkd9r1
B: EXCEPT 运算符 x;H#-^LxW=
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 -$pS
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C: INTERSECT 运算符 ]W,K}~!
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。 >z0~!!YZ
注:使用运算词的几个查询结果行必须是一致的。 /<Nb/#8
12、说明:使用外连接 m5KB #\
A、left outer join: ~50b$];y
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。 V>#iR>w_4,
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 NwQexYm1_
B:right outer join: z-(#Mlq:!
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。 .H1kl)~V
C:full outer join: nnBgTtsC]
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。 V\axOz!
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二、提升 r,p6J7/lfS
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) nquKeH
法一:select * into b from a where 1<>1 *SkUkqP9z
法二:select top 0 * into b from a aQax85
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 7 mulNq
insert into b(a, b, c) select d,e,f from b; S@suPkQ<>
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) nJ/ wtw
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 F?j;3@z[A
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 4m++>q
4、说明:子查询(表名1:a 表名2:b) ^+Ez[S{8
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) ejj|l
5、说明:显示文章、提交人和最后回复时间 >:l;W4j
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b oo\0X
6、说明:外连接查询(表名1:a 表名2:b) YJgw%UVJ5m
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c \=+s3p5N
7、说明:在线视图查询(表名1:a ) \ iL&Aq}BO
select * from (SELECT a,b,c FROM a) T where t.a > 1; Qy ;
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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 ?DVO\Cp
select * from table1 where time between time1 and time2 f_1#>]
select a,b,c, from table1 where a not between 数值1 and 数值2 L2ePWctq}
9、说明:in 的使用方法 !Ju?REH
select * from table1 where a [not] in ('值1','值2','值4','值6') 2A3;#v
10、说明:两张关联表,删除主表中已经在副表中没有的信息 \Cx)
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delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) <YbOO{
11、说明:四表联查问题: $)|
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select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... W(*:8}m,p
12、说明:日程安排提前五分钟提醒 e_J_rx
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ]pLQ;7f7D
13、说明:一条sql 语句搞定数据库分页 cmDskQ:
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 E-,74B&H
14、说明:前10条记录 A.9,p
select top 10 * form table1 where 范围 W>b(hVBE
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) qB3{65
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) fFXG;Q8&
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 =YX/]g|9K
(select a from tableA ) except (select a from tableB) except (select a from tableC) ]ABpOrg
17、说明:随机取出10条数据 ]Jj\**
select top 10 * from tablename order by newid() ok5
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18、说明:随机选择记录 &fYx0JT
select newid() b5YjhRimS
19、说明:删除重复记录 k4_Fn61J/
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) "s$v?voo
20、说明:列出数据库里所有的表名 1Giy|;2/
select name from sysobjects where type='U' L K9vvQz
21、说明:列出表里的所有的 ]*{QVn(
select name from syscolumns where id=object_id('TableName') P,RCbPC4
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。 g#ZR,q
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\V{0;mp
显示结果: `gqBJi
type vender pcs 9vL`|`Vau
电脑 A 1
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电脑 A 1 LGT\1u
光盘 B 2 ;VS;),h/
光盘 A 2 <FH3ePz
手机 B 3 bG+p
手机 C 3 '#<?QE!d2
23、说明:初始化表table1 x]%e_
TRUNCATE TABLE table1 84P^7[YX>
24、说明:选择从10到15的记录 ]}9cOb%I
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc !@-j!Ub
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三、技巧 JGZ,5RTq4-
1、1=1,1=2的使用,在SQL语句组合时用的较多 xMtl<Na
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ?n/:1LN,
如: %iIryv;
if @strWhere !='' _jef{j
begin yhEU*\:
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere V_U$JKJ1=
end D0PP
else U;Hu:q*
begin ,oDZ:";
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' pRXA!QfO
end j._9;HifZ
我们可以直接写成 ltt%X].[
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere >82Q!HaH
2、收缩数据库 E?&dZR
--重建索引 %Ua*}C
DBCC REINDEX D`e!CprF
DBCC INDEXDEFRAG >8SX ,
--收缩数据和日志 Z!6\KV]
DBCC SHRINKDB }"fP,:n"KN
DBCC SHRINKFILE ksY^w+>(!
3、压缩数据库 -w 2!k
dbcc shrinkdatabase(dbname) IGql^,b
4、转移数据库给新用户以已存在用户权限 U*/
exec sp_change_users_login 'update_one','newname','oldname' a#! Vi93
go 'O]_A57
5、检查备份集 /{7x|ay]
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ? $pGG
6、修复数据库 %xLziF
ALTER DATABASE [dvbbs] SET SINGLE_USER +d\"n
GO 1SkGG0
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DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK jD_(im5
GO KK]AX;
ALTER DATABASE [dvbbs] SET MULTI_USER 7*^\mycv
GO sx8mba(
7、日志清除 )QaJYC^+
SET NOCOUNT ON m*P~X*St
DECLARE @LogicalFileName sysname, 9R>A,x(
@MaxMinutes INT, :<ujk
@NewSize INT \UJ:PW$7
USE tablename -- 要操作的数据库名 o&*1Mx<+
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 wx(|$2{h
@MaxMinutes = 10, -- Limit on time allowed to wrap log. NNutpA}s
@NewSize = 1 -- 你想设定的日志文件的大小(M) 3-32q)8
-- Setup / initialize UOF5&>MLb
DECLARE @OriginalSize int S~YrXQ{_>-
SELECT @OriginalSize = size |Uy hH^
FROM sysfiles (5-"5<-@R
WHERE name = @LogicalFileName `;*=2M<c
SELECT 'Original Size of ' + db_name() + ' LOG is ' + -sO EL{
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ]9zc[_
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' a>sUq["
FROM sysfiles FlVGi3
WHERE name = @LogicalFileName I=f1kr
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CREATE TABLE DummyTrans 4OCz:t
(DummyColumn char (8000) not null) Ew4DumI
DECLARE @Counter INT, RZ|s[bU
@StartTime DATETIME, $q.8ve0&^
@TruncLog VARCHAR(255) $+JaEF`8
SELECT @StartTime = GETDATE(), VbBZ\`b
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' R9S7p)B
DBCC SHRINKFILE (@LogicalFileName, @NewSize) $g#X9/+<
EXEC (@TruncLog) .eZ4?|at.F
-- Wrap the log if necessary. jc;&g)Rv
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired !SiZA"
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ; {I{X}b
AND (@OriginalSize * 8 /1024) > @NewSize rVQ:7\=Z
BEGIN -- Outer loop. JEY%(UR8
SELECT @Counter = 0 sF_.9G)S0
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) "TtK!>!.
BEGIN -- update Gpe h#Q4x
INSERT DummyTrans VALUES ('Fill Log') QHMXQyr(
DELETE DummyTrans ~DqNA%Mb
SELECT @Counter = @Counter + 1 P;hjr;
END 3m7$$N|
EXEC (@TruncLog) _PNU*E%s<
END O|7q,bEm^
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Vize0fsD
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + uT]_pKm
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' FD_0FMZ9,
FROM sysfiles Fhxg^
WHERE name = @LogicalFileName ?{_dW=AQ1
DROP TABLE DummyTrans {!^HG+
SET NOCOUNT OFF U@f3V8CPy
8、说明:更改某个表 ?3KI}'}EM
exec sp_changeobjectowner 'tablename','dbo' jGI!}4_
9、存储更改全部表 ?/#HTg)!B
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 9IMRWtZWT
@OldOwner as NVARCHAR(128), =5dv38
@NewOwner as NVARCHAR(128) K<Yh'RvTD
AS *XtZ;os]
DECLARE @Name as NVARCHAR(128) woR((K] #G
DECLARE @Owner as NVARCHAR(128) .s7/bF
DECLARE @OwnerName as NVARCHAR(128) ,vg8iRa
DECLARE curObject CURSOR FOR s%4)}w;z
select 'Name' = name, .fo.mC@a
'Owner' = user_name(uid) YqNhD6
from sysobjects CoJaVLl
where user_name(uid)=@OldOwner \,p)
order by name /^/'9}7
OPEN curObject webT
FETCH NEXT FROM curObject INTO @Name, @Owner *WMcE$w/D
WHILE(@@FETCH_STATUS=0) ?0'bf y]
BEGIN |C>Yd*E,C
if @Owner=@OldOwner 0"
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begin ynP^|Ou
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 3: mF!
exec sp_changeobjectowner @OwnerName, @NewOwner qViky=/-
end V3@^bc!
-- select @name,@NewOwner,@OldOwner i>)Whr'e8
FETCH NEXT FROM curObject INTO @Name, @Owner I|WBT
END ]BAF
close curObject
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deallocate curObject )-
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GO ZP%^.wxC
10、SQL SERVER中直接循环写入数据 5^*
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declare @i int X/gh>MJJ<
set @i=1 [&+wW
while @i<30 p' /$)klt
begin >2VB.f
insert into test (userid) values(@i) hCr7%`
set @i=@i+1 }s{zy:1O
end qx_+mCZ
小记存储过程中经常用到的本周,本月,本年函数 z)|56
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Dateadd(wk,datediff(wk,0,getdate()),-1) r T*:1
Dateadd(wk,datediff(wk,0,getdate()),6) []LNNO],X
Dateadd(mm,datediff(mm,0,getdate()),0) DeXnE$XH
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ? `FI!3j
Dateadd(yy,datediff(yy,0,getdate()),0) @*%.V.
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 3QV|@5L`[
上面的SQL代码只是一个时间段 .' .|s?s
Dateadd(wk,datediff(wk,0,getdate()),-1) >DbG$V<v'
Dateadd(wk,datediff(wk,0,getdate()),6) ;Rwr5
就是表示本周时间段. Z71"d"
下面的SQL的条件部分,就是查询时间段在本周范围内的: 3j.f3~"
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) h ?p^DPo
而在存储过程中 l'3NiIX
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 2@e<II2ha8
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Itz_;+I.Mp