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。 ~+RrL,t#
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一、基础 b+CvA(*
1、说明:创建数据库 gKPqU @$*
CREATE DATABASE database-name Z yz)`>cB
2、说明:删除数据库 k9\n='OI
drop database dbname f|yq~3x)
3、说明:备份sql server 3zM>2)T-
--- 创建 备份数据的 device WS@8Z0@RD
USE master Dl}va
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' S|IDFDn
--- 开始 备份 ??P3gA
BACKUP DATABASE pubs TO testBack sP8_Y,
4、说明:创建新表 |FFMQ"
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) g^\>hjNX
根据已有的表创建新表: 2Myz[)<P_
A:create table tab_new like tab_old (使用旧表创建新表) i.ivHV~-
B:create table tab_new as select col1,col2... from tab_old definition only !#WJ(zSq
5、说明:删除新表 aprgThoD
drop table tabname @XKVdtG
6、说明:增加一个列 C$v
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Alter table tabname add column col type o 7 &q
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。 f_QZql
7、说明:添加主键: Alter table tabname add primary key(col) )L,Nh~
说明:删除主键: Alter table tabname drop primary key(col) ~@D!E/hZx
8、说明:创建索引:create [unique] index idxname on tabname(col....) l~*d0E-$
删除索引:drop index idxname M3)Id?|]6
注:索引是不可更改的,想更改必须删除重新建。 Vt4,?"
9、说明:创建视图:create view viewname as select statement 2-"`%rE
删除视图:drop view viewname w/CD-
10、说明:几个简单的基本的sql语句 9v}vCg
选择:select * from table1 where 范围 |q_Hiap#a
插入:insert into table1(field1,field2) values(value1,value2) GsE
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删除:delete from table1 where 范围 $[(FCS
更新:update table1 set field1=value1 where 范围 ;,u7)
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! %Vsg4DRy
排序:select * from table1 order by field1,field2 [desc] ?T[K{t;~jo
总数:select count as totalcount from table1 M;@/697G
求和:select sum(field1) as sumvalue from table1 `{J(S'a`
平均:select avg(field1) as avgvalue from table1 Xkp`1UTH
最大:select max(field1) as maxvalue from table1 \Q,5Ne'o
最小:select min(field1) as minvalue from table1 *eUxarI
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11、说明:几个高级查询运算词 2|8$@*-\
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A: UNION 运算符 v,c:cKj
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。 `%0k\,}V
B: EXCEPT 运算符 8uetv
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。 ,aSK L1
C: INTERSECT 运算符 >vQKCc|93
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。 lMXLd91
注:使用运算词的几个查询结果行必须是一致的。 8';huq@C{
12、说明:使用外连接 /KCIb:U
A、left outer join: JB!KOzw
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。 _We4%
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 6J\A%i
B:right outer join: Dt+uf5o(
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。 IeE6?!,)
C:full outer join: 5'3H$%dC
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。 T4"*w
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二、提升 :}fIu?hCA
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) DYL \=ya1
法一:select * into b from a where 1<>1 &vS @-K
法二:select top 0 * into b from a ",Fqpu&M
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 0kld77tn
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insert into b(a, b, c) select d,e,f from b; Csx??T_>r
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) ~`Rooh3m
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 @LDu08lr
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. }F)eA1
4、说明:子查询(表名1:a 表名2:b) ~^"s.Lsb
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) dw< b}2
5、说明:显示文章、提交人和最后回复时间 !tv+,l&L
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 0[SrRpD
6、说明:外连接查询(表名1:a 表名2:b) BQ77n2(@
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 1BA5|
7、说明:在线视图查询(表名1:a ) P;lDri
select * from (SELECT a,b,c FROM a) T where t.a > 1; >]l7AZ:,
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 u=!n9W~"
select * from table1 where time between time1 and time2 <o&\/uO~H
select a,b,c, from table1 where a not between 数值1 and 数值2
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9、说明:in 的使用方法 uF\f>E)/N%
select * from table1 where a [not] in ('值1','值2','值4','值6') l#%G~c8x
10、说明:两张关联表,删除主表中已经在副表中没有的信息 {DGnh1
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ^o6&|q
11、说明:四表联查问题: 83YQ c
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 ..... U~[ tp1Z)
12、说明:日程安排提前五分钟提醒 wE09%
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 zRF+D+
13、说明:一条sql 语句搞定数据库分页 V']1j
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 u-#J!Z<T8
14、说明:前10条记录 -Mufo.Jz1o
select top 10 * form table1 where 范围 a6.0$'
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.) ^>!~%Vv7!
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Z <vTr6?
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 3gU*,K7
(select a from tableA ) except (select a from tableB) except (select a from tableC) R//S(eU68\
17、说明:随机取出10条数据 &dI;o$t
select top 10 * from tablename order by newid() nL-kBW Ed>
18、说明:随机选择记录 -&_;x&k
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select newid() +^@6{1
19、说明:删除重复记录 _'DZoOH|VE
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) \jThbCb
20、说明:列出数据库里所有的表名 7
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select name from sysobjects where type='U' WCZeY?_^c
21、说明:列出表里的所有的 YXjWk),
select name from syscolumns where id=object_id('TableName') TP&&' 4?D1
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 5 iP{)
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type v?(9ZY]
显示结果: &IgH]?t
type vender pcs P0^7hSo
电脑 A 1 cvl1X"
电脑 A 1 *Wz\FixP0
光盘 B 2 n!t][d/g+
光盘 A 2 LuW^Ga"E
手机 B 3 ,Taq~
手机 C 3 23WlUM
23、说明:初始化表table1 b&Go'C{p
TRUNCATE TABLE table1 (J/!9NS:
24、说明:选择从10到15的记录 9$:+5f,%a
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 7[u$!.4{*
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三、技巧 j*}2AI
1、1=1,1=2的使用,在SQL语句组合时用的较多 "jG-)k`a
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ,}_uk]AQ
如: $>y
if @strWhere !='' '2.11cM3
begin ?3+>% bO
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere :*{\oqFn~$
end _Zs]za.#)|
else gdfG3d$4
begin rCdf*;
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' bv8GJ #
end T hLR<\
我们可以直接写成 !`F^LXGA
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere f'3sT(1&
2、收缩数据库 Kw^tvRt'*
--重建索引 f.y~ Sew
DBCC REINDEX j>t*k!db
DBCC INDEXDEFRAG -S %)2(f^
--收缩数据和日志 *<nfA}
DBCC SHRINKDB |;6l1]hk6
DBCC SHRINKFILE K~JXP5`(
3、压缩数据库 MW6KEiQ"
dbcc shrinkdatabase(dbname) @:"GgkyDl#
4、转移数据库给新用户以已存在用户权限 koAM",5D
exec sp_change_users_login 'update_one','newname','oldname' jIs2R3B
go #[{xEVf
5、检查备份集 mjz<,s`D
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' '+{dr\nJ
6、修复数据库 %!e;sL~&
ALTER DATABASE [dvbbs] SET SINGLE_USER PC}m.tE
GO ;BMm47<
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK rCa2$#Z
GO z7P]g
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ALTER DATABASE [dvbbs] SET MULTI_USER !%{s[eO\
GO ^U4|TR6mub
7、日志清除 Z6vm!#\
SET NOCOUNT ON h8lI#Gs
DECLARE @LogicalFileName sysname, pe1 _E
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@MaxMinutes INT, B 8ycr~
@NewSize INT ~NtAr1
USE tablename -- 要操作的数据库名 qxe%RYdA'j
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 qW6}^aa
@MaxMinutes = 10, -- Limit on time allowed to wrap log. j,/t<@S>
@NewSize = 1 -- 你想设定的日志文件的大小(M) `F<[\@\d5
-- Setup / initialize B=`"!?we
DECLARE @OriginalSize int 9&`ejeD
SELECT @OriginalSize = size .wfN.Z
FROM sysfiles Z*rA~`@K6
WHERE name = @LogicalFileName +2+wNFU
SELECT 'Original Size of ' + db_name() + ' LOG is ' + .4NQ2k1io
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + |ozlaj
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' zUhJr$N$
FROM sysfiles ?~5J!|r#
WHERE name = @LogicalFileName f{Dc R"
CREATE TABLE DummyTrans MYb^ILz H3
(DummyColumn char (8000) not null) aab?hR
DECLARE @Counter INT, HKdR?HM1
@StartTime DATETIME, !bHM:!6^
@TruncLog VARCHAR(255) sC .R.
SELECT @StartTime = GETDATE(), {PCf'n
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' E |A,NPf%I
DBCC SHRINKFILE (@LogicalFileName, @NewSize) T?Dq2UW
EXEC (@TruncLog) xf.2Ig
-- Wrap the log if necessary. >xt*( j&}
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 5E+k}S]M$
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) KQ x<{-G6
AND (@OriginalSize * 8 /1024) > @NewSize +i[w& P
BEGIN -- Outer loop. Xkv+"F=-
SELECT @Counter = 0 F& 'HZX
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ,T|%vqbmw
BEGIN -- update &Tf R].
INSERT DummyTrans VALUES ('Fill Log') Mwdw7MZ"S
DELETE DummyTrans 69v[*InSd
SELECT @Counter = @Counter + 1 m9Uoq[1
END E+&]96*Lby
EXEC (@TruncLog) drQioH-
END ",ic"
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SELECT 'Final Size of ' + db_name() + ' LOG is ' + 2.K"+%
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + {mp;^/O`er
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' \JLiA>@@
FROM sysfiles q$Ol"K@
WHERE name = @LogicalFileName (pjmE7`"P
DROP TABLE DummyTrans afZPju"-
SET NOCOUNT OFF zq5_&AeW
8、说明:更改某个表 )^&)f!f
exec sp_changeobjectowner 'tablename','dbo' B`4[@$
9、存储更改全部表 %-4e8d74/
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch sKX%<n$
@OldOwner as NVARCHAR(128), S"=oU}'|
@NewOwner as NVARCHAR(128) 8elT/Wl
AS ^w<:UE2a!
DECLARE @Name as NVARCHAR(128) `f^`i~c\
DECLARE @Owner as NVARCHAR(128) Ccocv>=Q&J
DECLARE @OwnerName as NVARCHAR(128) a91Q*X%
DECLARE curObject CURSOR FOR /rNY;qXM
select 'Name' = name, pr-{/6j6
'Owner' = user_name(uid) QsmG(1=
from sysobjects X
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where user_name(uid)=@OldOwner .~5cNu'#m
order by name K6,5C0
OPEN curObject Oed&B
FETCH NEXT FROM curObject INTO @Name, @Owner 7 #,+Q(2
WHILE(@@FETCH_STATUS=0) (WW,]#^
BEGIN a<V=C
if @Owner=@OldOwner S)"5X)mq
begin |7zm!^t$
set @OwnerName = @OldOwner + '.' + rtrim(@Name) Oh:SH|=]#
exec sp_changeobjectowner @OwnerName, @NewOwner F|V co]"S1
end OD"eB?
-- select @name,@NewOwner,@OldOwner tE{7S/?h
FETCH NEXT FROM curObject INTO @Name, @Owner
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END iR#jBqXD
close curObject ,gU9ywg
deallocate curObject ?.A6HrAPB
GO 'ce9v@(0
10、SQL SERVER中直接循环写入数据 utwh"E&W
declare @i int <,0&Ox
set @i=1 tS2lex%
while @i<30 eT+MN`
begin ?<w +{
insert into test (userid) values(@i) "VWxHRVg4M
set @i=@i+1 s=huOjKL]
end +V|]:{3W
小记存储过程中经常用到的本周,本月,本年函数 /$rS0@p
Dateadd(wk,datediff(wk,0,getdate()),-1) nWZrB s
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Dateadd(wk,datediff(wk,0,getdate()),6) "`:#sF9S
Dateadd(mm,datediff(mm,0,getdate()),0) qc\o>$-:`
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) }7$\F!R
Dateadd(yy,datediff(yy,0,getdate()),0) YA^9, q6u?
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) CSU> nIE0
上面的SQL代码只是一个时间段 $zCUQthL@
Dateadd(wk,datediff(wk,0,getdate()),-1) {uj9fE,)
Dateadd(wk,datediff(wk,0,getdate()),6) j)F~C8*
就是表示本周时间段. %h%r6EB1F
下面的SQL的条件部分,就是查询时间段在本周范围内的: 2
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Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) rMlbj2T
而在存储过程中 XB;;OP12
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) %
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select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) @V :b Co