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。 %TB(E<p`
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一、基础 1U 6B$(V^i
1、说明:创建数据库 bc)>h!'Y
CREATE DATABASE database-name C|'DKT4M&
2、说明:删除数据库 ([>ecS@eO
drop database dbname PRKZg]?
3、说明:备份sql server )!T~l(g
--- 创建 备份数据的 device NGx3f3 9
USE master | f#wbw
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 8nz({Mb9Z
--- 开始 备份 Y
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BACKUP DATABASE pubs TO testBack Syk)S<
4、说明:创建新表 \Wbmmd}8
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) vQAFg G
根据已有的表创建新表: FFHq':v
A:create table tab_new like tab_old (使用旧表创建新表) nxLuzf4U5
B:create table tab_new as select col1,col2... from tab_old definition only QV;o9j
5、说明:删除新表 e+
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drop table tabname V Z(/g"9
6、说明:增加一个列
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Alter table tabname add column col type qQ@| Cj
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。 WK~H]w
7、说明:添加主键: Alter table tabname add primary key(col) O%bbyR2
说明:删除主键: Alter table tabname drop primary key(col) d*(aue=
8、说明:创建索引:create [unique] index idxname on tabname(col....) 1b,a3w(:1
删除索引:drop index idxname &!!*xv-z
注:索引是不可更改的,想更改必须删除重新建。 >I5:@6
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9、说明:创建视图:create view viewname as select statement B9v>="F
删除视图:drop view viewname -YRIe<}E -
10、说明:几个简单的基本的sql语句 U1RU2M]v
选择:select * from table1 where 范围 91-bz^=xO
插入:insert into table1(field1,field2) values(value1,value2) Up9{aX
删除:delete from table1 where 范围 Bo 35L:r|
更新:update table1 set field1=value1 where 范围 PwY/VGT
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 'ofj1%c
排序:select * from table1 order by field1,field2 [desc] dzVi ~wt_&
总数:select count as totalcount from table1 @MW@mP)#
求和:select sum(field1) as sumvalue from table1 +-9vrEB
平均:select avg(field1) as avgvalue from table1 Q&9yrx.
最大:select max(field1) as maxvalue from table1 )uPJ?
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最小:select min(field1) as minvalue from table1 S-Uod y
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11、说明:几个高级查询运算词 rfXxg^
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A: UNION 运算符 . "Ms7=
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。 1{}p_"s>
B: EXCEPT 运算符 JA^o/%a^
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。 ^X#y'odtbS
C: INTERSECT 运算符 ]
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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。 ! 'zd(kv<
注:使用运算词的几个查询结果行必须是一致的。 T$Z9F^w
12、说明:使用外连接 [ks_wvY:'
A、left outer join: tUn>=>cWP
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。 "wUIsuG/p
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 GES}o9?#
B:right outer join: rxY|&!f
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。 _Q V=3UWP
C:full outer join: Di9RRHn&q
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。 U82a]i0
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二、提升 ofvR0yV
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) `e[S Zj\
法一:select * into b from a where 1<>1 2u{~35
法二:select top 0 * into b from a w)btv{*
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) k"wQ9=HP7
insert into b(a, b, c) select d,e,f from b; qxL\G &~
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) 7qKz_O
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 rd <m:r
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. w5FIHYl6B
4、说明:子查询(表名1:a 表名2:b) I-#H+\S
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) F(")ga$r
5、说明:显示文章、提交人和最后回复时间 &@=Jm
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b }=R]<`Sj.j
6、说明:外连接查询(表名1:a 表名2:b) QM$UxWo-
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ZOK!SBn^?
7、说明:在线视图查询(表名1:a ) 5_yQI D%Sq
select * from (SELECT a,b,c FROM a) T where t.a > 1; 6[bopin
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 D9rQ%|}S
select * from table1 where time between time1 and time2 6BE,L
select a,b,c, from table1 where a not between 数值1 and 数值2 .i0K-B
9、说明:in 的使用方法 kpOdyn(
select * from table1 where a [not] in ('值1','值2','值4','值6') hpdI5
10、说明:两张关联表,删除主表中已经在副表中没有的信息 K_Y-N!h
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) >e]g T
11、说明:四表联查问题: (;NJ<x
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 ..... ''17(%
12、说明:日程安排提前五分钟提醒 woI5a ee|
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 Ee>VA_ss
13、说明:一条sql 语句搞定数据库分页 dQ:,pe7A
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 z]7 WC
14、说明:前10条记录 A(Ct^/x-
select top 10 * form table1 where 范围 b?wrOS
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.) Mz+I
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ULx:2jz
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 1{uxpYAP=
(select a from tableA ) except (select a from tableB) except (select a from tableC) kG^76dAQL
17、说明:随机取出10条数据 n ]%2Kx
select top 10 * from tablename order by newid() B|`?hw@g+
18、说明:随机选择记录 5epI'D
select newid() a@}.96lStD
19、说明:删除重复记录 iTxWXij
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) (leX` SN0u
20、说明:列出数据库里所有的表名 @N'n>8Wn
select name from sysobjects where type='U' r&=ulg
21、说明:列出表里的所有的 ,BdObx
select name from syscolumns where id=object_id('TableName') ct+F\:e
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。 $QbJT`,mr
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 q~{)
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显示结果: c
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type vender pcs *)^6'4=
电脑 A 1 PgtLyzc
电脑 A 1 )W\)37=.
光盘 B 2 ]4~Yi1]
光盘 A 2 +IZ=E
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手机 B 3 X4 !93
手机 C 3 UB~K/r`.|
23、说明:初始化表table1 e02Hf{eOfw
TRUNCATE TABLE table1 y4\X~5kU
24、说明:选择从10到15的记录 iSfRJ:_&6
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc S!K<kn`E3
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三、技巧 J,$xQ?,wE
1、1=1,1=2的使用,在SQL语句组合时用的较多 .jRI
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, Y1r$;;sH
如: 1UQ,V`y
if @strWhere !='' :>-zT[Lcn
begin XQ1]F{?/H
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere E|pT6
end ]w *"KG!(
else 1$cl "d`~
begin KXKT5E$
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ,fjY|ip
end Qt u;_
我们可以直接写成 ^[hAj>7_8$
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere =OufafZb
2、收缩数据库 7cc^n\c?Y
--重建索引 FDoPW~+[
DBCC REINDEX txEN7!
DBCC INDEXDEFRAG b'4a;k!rS
--收缩数据和日志 a\sK{`|X*
DBCC SHRINKDB _hnsH
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DBCC SHRINKFILE #H$lBCWI
3、压缩数据库 e;i 6C%DB
dbcc shrinkdatabase(dbname) QQ?t^ptv
4、转移数据库给新用户以已存在用户权限 z+Xr2B
exec sp_change_users_login 'update_one','newname','oldname' pPL=(9d
go $S>'0mL
5、检查备份集 ^f[6NYS?
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' P9!awLM-
6、修复数据库 he|Q(?
ALTER DATABASE [dvbbs] SET SINGLE_USER D:`Q\za
GO Mi]^wCF
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK (KI9j7
GO K6{wM
ALTER DATABASE [dvbbs] SET MULTI_USER &C'^YF_^0
GO bvD}N<>3N
7、日志清除 `%YMUBaI
SET NOCOUNT ON |s3;`Nxu7
DECLARE @LogicalFileName sysname, m|NZ093d
@MaxMinutes INT, u|KjoO
@NewSize INT Kp7DI0~
USE tablename -- 要操作的数据库名 Kebr>t8^
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 hp f0fU
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ,#;hI{E
@NewSize = 1 -- 你想设定的日志文件的大小(M) MkW=sD_
-- Setup / initialize %??v?M*
DECLARE @OriginalSize int Gf8 ^nfr
SELECT @OriginalSize = size 2:
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FROM sysfiles l]G
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WHERE name = @LogicalFileName 628iN%[-
SELECT 'Original Size of ' + db_name() + ' LOG is ' + #WjQ'c:
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + $ :I{
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' @ ]u@e4T
FROM sysfiles GR|\OJ<2
WHERE name = @LogicalFileName RUY7Y?
CREATE TABLE DummyTrans O=__w *<
(DummyColumn char (8000) not null) ")KqPD6k
DECLARE @Counter INT, !-M Y<'
@StartTime DATETIME, -k + jMH
@TruncLog VARCHAR(255) =!-} q
SELECT @StartTime = GETDATE(), ?22U0UF
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 'p5M|h\:T
DBCC SHRINKFILE (@LogicalFileName, @NewSize) &~2m@X(o
EXEC (@TruncLog) 3JC uM_y
-- Wrap the log if necessary. 1 b7jNkQ
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired b |:Y3_>
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) "{8j!+]4i
AND (@OriginalSize * 8 /1024) > @NewSize JuZkE9C,${
BEGIN -- Outer loop. Mbc&))A
SELECT @Counter = 0 qu^g~"s
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) #^$_/Q#C
BEGIN -- update ]RAh['u|
INSERT DummyTrans VALUES ('Fill Log') 1IoW}yT
DELETE DummyTrans pPa]@ z~O
SELECT @Counter = @Counter + 1 .B~}hjOZK
END B*_K}5UO
EXEC (@TruncLog) gaN/
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END uD/@d'd_4L
SELECT 'Final Size of ' + db_name() + ' LOG is ' + z5gVP8*z5
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ]Ea-MeH
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' t
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FROM sysfiles z~2{`pET
WHERE name = @LogicalFileName _-BP?'lN
DROP TABLE DummyTrans lU
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SET NOCOUNT OFF D\M"bf>q1
8、说明:更改某个表 NzAh3k
exec sp_changeobjectowner 'tablename','dbo' 3IRur,|'
9、存储更改全部表 OxDqLX
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Dtd~}-_Q
@OldOwner as NVARCHAR(128), \v&zsv\B@
@NewOwner as NVARCHAR(128) U[MeK)*
AS xO_>%F^?
DECLARE @Name as NVARCHAR(128) HW]?%9a
DECLARE @Owner as NVARCHAR(128) q\@_L.tc[
DECLARE @OwnerName as NVARCHAR(128) =4` wYh
DECLARE curObject CURSOR FOR umns*U%T;
select 'Name' = name, T1q27I
'Owner' = user_name(uid) i&m_G5u88
from sysobjects U;/2\Ii
where user_name(uid)=@OldOwner QM8Ic,QFvo
order by name _<RTes
OPEN curObject ,c"J[$i$
FETCH NEXT FROM curObject INTO @Name, @Owner ^?RH<z
WHILE(@@FETCH_STATUS=0) dwk%!%
BEGIN ]y.V#,6e
if @Owner=@OldOwner G@/iK/>5|`
begin \dCGu~bT
set @OwnerName = @OldOwner + '.' + rtrim(@Name) #f"eZAQ {
exec sp_changeobjectowner @OwnerName, @NewOwner z'l
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end ~;9n6U
-- select @name,@NewOwner,@OldOwner {@CQ
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FETCH NEXT FROM curObject INTO @Name, @Owner -+{[.U<1jk
END x</4/d
close curObject T/E=?kBR
deallocate curObject T#Q7L~?zY
GO m"rht:v5
10、SQL SERVER中直接循环写入数据 Zb2pZhkW
declare @i int Y_Fn)(
set @i=1 6 eryf?
while @i<30 PwW$=M{\.
begin "LTw;& y
insert into test (userid) values(@i) A:ts_*
set @i=@i+1 `E1G9BbU
end C jf<,x$
小记存储过程中经常用到的本周,本月,本年函数 6HZtdRQF
Dateadd(wk,datediff(wk,0,getdate()),-1) 27 XM&ZrZ
Dateadd(wk,datediff(wk,0,getdate()),6) q;bw}4
Dateadd(mm,datediff(mm,0,getdate()),0) MlYm\x8{M
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) (1|wM+)"
Dateadd(yy,datediff(yy,0,getdate()),0) Yw#fQFm
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 9vP;i= fr
上面的SQL代码只是一个时间段 @]q^OMLY
Dateadd(wk,datediff(wk,0,getdate()),-1) Bc.de&Bxz_
Dateadd(wk,datediff(wk,0,getdate()),6) zoi0Z
就是表示本周时间段. ke8g tbm
下面的SQL的条件部分,就是查询时间段在本周范围内的: la<.B^
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) _^Q!cB'~/`
而在存储过程中 ^7\kvW
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) x?o#}:S
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) RAl/p9\A+