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。 bVbh| AA
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一、基础 o`EL)K{
1、说明:创建数据库 1~|o@CO
CREATE DATABASE database-name >
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2、说明:删除数据库 .w@o%AO_
drop database dbname 1638U1
3、说明:备份sql server +)cjW"9
--- 创建 备份数据的 device L6jD4ec8
USE master Px$4.b[{_Y
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' *w/})Y3^
--- 开始 备份 ;t_'87h$y
BACKUP DATABASE pubs TO testBack VD).UdUn
4、说明:创建新表 !-OPzfHrI
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) $vQ#ah/k
根据已有的表创建新表: ;n"Nv}<C
A:create table tab_new like tab_old (使用旧表创建新表) "'8^OZR
B:create table tab_new as select col1,col2... from tab_old definition only Q^_*&},V
5、说明:删除新表 N-~Uu6zr
drop table tabname $!Pm*s
6、说明:增加一个列 *$4 EXwt'
Alter table tabname add column col type #$ Q2ijT0
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。 V7pe|]%r
7、说明:添加主键: Alter table tabname add primary key(col)
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说明:删除主键: Alter table tabname drop primary key(col) ;rK=
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8、说明:创建索引:create [unique] index idxname on tabname(col....) ^#Ruw?D
删除索引:drop index idxname js~?y|e8k
注:索引是不可更改的,想更改必须删除重新建。 U11bQ4ak
9、说明:创建视图:create view viewname as select statement h\@\*Xz<v
删除视图:drop view viewname SBNeN]
10、说明:几个简单的基本的sql语句 |d@%Vb_
选择:select * from table1 where 范围 82z\^a
插入:insert into table1(field1,field2) values(value1,value2) 5Lo\[K>j
删除:delete from table1 where 范围 Z fQzA}QD
更新:update table1 set field1=value1 where 范围 $XOs(>~"r
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Tw{}Ht_Qq
排序:select * from table1 order by field1,field2 [desc] YKk*QcAn
总数:select count as totalcount from table1 ^/H9`z;
求和:select sum(field1) as sumvalue from table1 <x^Ab#K"
平均:select avg(field1) as avgvalue from table1 (H/2{##
最大:select max(field1) as maxvalue from table1 =gYKAr^p5
最小:select min(field1) as minvalue from table1 h:J0d~u
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11、说明:几个高级查询运算词 \N[Z58R !z
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A: UNION 运算符 AD** 4E
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。 sFvu@Wm'7W
B: EXCEPT 运算符 ]rpU3 3
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。 3/j^Ao\fw
C: INTERSECT 运算符 PqhR^re0.
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。 FM80F_G^z
注:使用运算词的几个查询结果行必须是一致的。 gYtv`O
12、说明:使用外连接 9;L5#/E
A、left outer join: Ui^~A
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。 8`0/?MZ)
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 ./iC
B:right outer join: I 19 /
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。 ) Ekd
C:full outer join: O/|,rAE
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。 TVVr<r
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二、提升 ]WO0v`xh
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ^uDNArDmj5
法一:select * into b from a where 1<>1 T&ECGF;Y/
法二:select top 0 * into b from a FS(bEAk}
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) MHm=X8eg
insert into b(a, b, c) select d,e,f from b; R?/!7
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) hJ>Kfm
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 Ci}v +
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Dm")\"5\?
4、说明:子查询(表名1:a 表名2:b) fW'@+<b
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) m,u5S=3A{!
5、说明:显示文章、提交人和最后回复时间 "L(4 EcO@
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b >\/H2j
6、说明:外连接查询(表名1:a 表名2:b) v}Gpw6
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c <#[_S$54
7、说明:在线视图查询(表名1:a ) <8JV`dTywC
select * from (SELECT a,b,c FROM a) T where t.a > 1; &7}\mnhB
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 :cvZk|b%
select * from table1 where time between time1 and time2 &V$qIvN$
select a,b,c, from table1 where a not between 数值1 and 数值2 tm"9`
9、说明:in 的使用方法 wU9H=w^
select * from table1 where a [not] in ('值1','值2','值4','值6') o9j*Yz
10、说明:两张关联表,删除主表中已经在副表中没有的信息 }%&hxhR^t3
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) pZYcCc>6&
11、说明:四表联查问题: \BoRYb9h
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 ..... i>]1E^yF
12、说明:日程安排提前五分钟提醒
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SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ^tw\F7
13、说明:一条sql 语句搞定数据库分页 QM"\;l??
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 \hm;p
14、说明:前10条记录 :|Ckr-k"1e
select top 10 * form table1 where 范围 c Nhy.Z~D
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.) XL`*Tbx
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) X\z`S##kj
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 g}cb>'=={
(select a from tableA ) except (select a from tableB) except (select a from tableC) xla64Qld
17、说明:随机取出10条数据 +*O$]Hh
select top 10 * from tablename order by newid() zq:+e5YT?T
18、说明:随机选择记录 o~aK[
select newid() a5)<roWQ
19、说明:删除重复记录 U)f;*{U
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 5-=&4R\k
20、说明:列出数据库里所有的表名 0wh4sKm[X
select name from sysobjects where type='U' K4r"Q*h
21、说明:列出表里的所有的 N=JZtf/i
select name from syscolumns where id=object_id('TableName') k\ 2.\Lwb
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。 $$,/F
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 3:S>MFRn.3
显示结果: mMz^I7$
type vender pcs 4
8}\
电脑 A 1 ZFJqI
电脑 A 1 rz@FUU:&
光盘 B 2 3pV^Oe^9
光盘 A 2 LU=<?"N6
手机 B 3 $ykujyngS4
手机 C 3 ^|P/D
23、说明:初始化表table1 \8KAK3i'
TRUNCATE TABLE table1 g }%$VUSA
24、说明:选择从10到15的记录 bzl-|+!yB
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc {mkD{2)KQ
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三、技巧 5>S<9A|Q
1、1=1,1=2的使用,在SQL语句组合时用的较多 Xcy Xju#"p
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 9On0om>
如: THOXs;
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if @strWhere !='' /^2&@P7
begin zL%ruWNG
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere gf&\)"
end `veq/!
else 2fa1jl
begin 6AA"JX
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' y|+n77[Gv
end :Sd"~\N+
我们可以直接写成 (FY<%.Pa
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 6>hW.aq}
2、收缩数据库 3SeM:OYq]s
--重建索引 Jtv~n
DBCC REINDEX /}ADV2sF
DBCC INDEXDEFRAG o)M=; !
--收缩数据和日志 kf Xg\6uKc
DBCC SHRINKDB ag7(nn0!
DBCC SHRINKFILE 1 p|h\H
3、压缩数据库 Za>0&Fnf
dbcc shrinkdatabase(dbname) Cb1fTl%
4、转移数据库给新用户以已存在用户权限 x=7qC#+)
exec sp_change_users_login 'update_one','newname','oldname' z5UY0>+VdS
go [8h~:.d`
5、检查备份集 QrX 5Kwq
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' )M:pg%
6、修复数据库 8etNS~^
ALTER DATABASE [dvbbs] SET SINGLE_USER U.kTdNSp
GO :mI[fQ
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK aOOkC&%
GO fPj*qi
ALTER DATABASE [dvbbs] SET MULTI_USER NmH:/xU?^
GO rDEdMT
7、日志清除 Yqz
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SET NOCOUNT ON h%0FKi^
DECLARE @LogicalFileName sysname, %z_L}L
@MaxMinutes INT, $.g)%#h:
@NewSize INT kvoEnwBe_
USE tablename -- 要操作的数据库名 PAcbC|y
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Cbq|<p# #o
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 'y?
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@NewSize = 1 -- 你想设定的日志文件的大小(M) WNa#X]*E)
-- Setup / initialize -:jC.}
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DECLARE @OriginalSize int Bt?.8H6Y
SELECT @OriginalSize = size _]/&NSk
FROM sysfiles yJMHm8OB7
WHERE name = @LogicalFileName AgU 7U/yk
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 8va&*J?
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + b~L8m4L
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' % njcWVP;
FROM sysfiles qUuvM
WHERE name = @LogicalFileName wvuh
CREATE TABLE DummyTrans yrgb6)]nm@
(DummyColumn char (8000) not null) D,<#pNO_
DECLARE @Counter INT, giNyD4uO
@StartTime DATETIME, [h=[@jiB
@TruncLog VARCHAR(255) (F.vVldBy
SELECT @StartTime = GETDATE(), E~| XY9U36
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' zB@@Gs>
DBCC SHRINKFILE (@LogicalFileName, @NewSize) }8\"oA6
EXEC (@TruncLog) V!3.MQM
-- Wrap the log if necessary. (+=TKI<=
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ;=ci7IT'
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) OD~TWT_
AND (@OriginalSize * 8 /1024) > @NewSize y~jYGN
BEGIN -- Outer loop. aN}l&4d
SELECT @Counter = 0 gL-\@4\wc
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) puPYM"
BEGIN -- update =w/S{yC
INSERT DummyTrans VALUES ('Fill Log') 50Kv4a"
DELETE DummyTrans j}devpO
SELECT @Counter = @Counter + 1 !~5=tK
END VdfV5"
EXEC (@TruncLog) Hc"FW5R
END h4 X >
SELECT 'Final Size of ' + db_name() + ' LOG is ' + u}L;/1,B
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + RE?j)$y?`
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' R/UL4R,)^
FROM sysfiles *\5o0~~8J
WHERE name = @LogicalFileName Db5y";T
DROP TABLE DummyTrans N`Q[OFe
SET NOCOUNT OFF TzW1+DxM5
8、说明:更改某个表 W2CQk
exec sp_changeobjectowner 'tablename','dbo' z/IZ ;K_e
9、存储更改全部表 9"TPAywd
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch V(LE4P1
@OldOwner as NVARCHAR(128), j & x=?jX
@NewOwner as NVARCHAR(128)
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AS Nsd7?|@HI
DECLARE @Name as NVARCHAR(128) 6IQkP9P(
DECLARE @Owner as NVARCHAR(128) @jp}WwC/
DECLARE @OwnerName as NVARCHAR(128) wV,l }Xb-
DECLARE curObject CURSOR FOR 1sHaG
select 'Name' = name, nLfITr|5
'Owner' = user_name(uid) EEJsNF
from sysobjects FlPPz
where user_name(uid)=@OldOwner |,G=k,?_p
order by name ONkHHyT
OPEN curObject "++q.y
FETCH NEXT FROM curObject INTO @Name, @Owner 52L* :|b
WHILE(@@FETCH_STATUS=0) 2'8$I}h
BEGIN ]("5O V5
if @Owner=@OldOwner BW61WH?
begin eqyZ|6
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 4[ S0~O{r
exec sp_changeobjectowner @OwnerName, @NewOwner ]J
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end D{](5?$`|
-- select @name,@NewOwner,@OldOwner xz+Y 1fYT
FETCH NEXT FROM curObject INTO @Name, @Owner Ua@rp3fr
END t ._PS3
close curObject #>|l"1
deallocate curObject Q/%(&4>'y
GO _/W[=c
10、SQL SERVER中直接循环写入数据 |vZ\tQ
declare @i int :.-z) C}
set @i=1 hm%'k~
while @i<30 fC_dSM[{c
begin ~ E)[!y
insert into test (userid) values(@i) QL>G-Rp
set @i=@i+1 1GnT^u y/
end (;V=A4F-D
小记存储过程中经常用到的本周,本月,本年函数 r|XNS>V ,$
Dateadd(wk,datediff(wk,0,getdate()),-1) LiyEF&_u
Dateadd(wk,datediff(wk,0,getdate()),6) D<rO:Er?*a
Dateadd(mm,datediff(mm,0,getdate()),0) m[7i<'+S
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) Y2
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Dateadd(yy,datediff(yy,0,getdate()),0) [mSK!Y@u
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) DR o@gYDn
上面的SQL代码只是一个时间段 @)8QxI^3[
Dateadd(wk,datediff(wk,0,getdate()),-1) g& yR -
Dateadd(wk,datediff(wk,0,getdate()),6) jb' hqz
就是表示本周时间段. zX-6]j;
下面的SQL的条件部分,就是查询时间段在本周范围内的: E6SGK,f0D
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) OQ$77]XtvL
而在存储过程中 ^@
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) kU8V,5
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) J?XEF@?'G