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。 IEV3(qzt
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一、基础 GeN8_i[
1、说明:创建数据库 W`],
CREATE DATABASE database-name 8Pklw^k
2、说明:删除数据库 RRy3N
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drop database dbname
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3、说明:备份sql server JpDc3^B*
--- 创建 备份数据的 device 6vz9r)L
USE master D,+I)-k<
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' F7^d@hSV
--- 开始 备份 :Vq gmn
BACKUP DATABASE pubs TO testBack M:h~;+s
4、说明:创建新表 Ow=` tv$l
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 93:s[bmx
根据已有的表创建新表: H@er" boi
A:create table tab_new like tab_old (使用旧表创建新表) +O:Qw[BL/Z
B:create table tab_new as select col1,col2... from tab_old definition only @=)_PG
5、说明:删除新表 0V*L",9M
drop table tabname zw^jIg$
6、说明:增加一个列 ^1U2&S
Alter table tabname add column col type V0R;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。 6sl*Ko[
7、说明:添加主键: Alter table tabname add primary key(col) Kx 6_Vp
说明:删除主键: Alter table tabname drop primary key(col) ,%X~/V
8、说明:创建索引:create [unique] index idxname on tabname(col....) X\\WQxj
删除索引:drop index idxname ;<%~g8:XL
注:索引是不可更改的,想更改必须删除重新建。 c]O3pcU
9、说明:创建视图:create view viewname as select statement <1]#E@
删除视图:drop view viewname 5nzkZw
10、说明:几个简单的基本的sql语句 )` S,vF~
选择:select * from table1 where 范围 GOHRBV
插入:insert into table1(field1,field2) values(value1,value2) JI5?,
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删除:delete from table1 where 范围 ^lB'7#7
更新:update table1 set field1=value1 where 范围 %"@KuqV
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! $xmltvaF
排序:select * from table1 order by field1,field2 [desc] @jg*L2L6
总数:select count as totalcount from table1 /AWV@'
求和:select sum(field1) as sumvalue from table1 :*TfGV
平均:select avg(field1) as avgvalue from table1 h,<%cvU=
最大:select max(field1) as maxvalue from table1 iNf+ -C3
最小:select min(field1) as minvalue from table1 ihKnZcI$i
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11、说明:几个高级查询运算词 "y/GK1C
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A: UNION 运算符 6Km@A M]
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。 G_=`&i"4
B: EXCEPT 运算符 SZH,I&8
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。 dNG>:p
C: INTERSECT 运算符 axnkuP(
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。 71nXROB
注:使用运算词的几个查询结果行必须是一致的。 $+zev$f
12、说明:使用外连接 Q$G!-y+"i
A、left outer join: MzsDWx;eJ
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 ge?1ez2
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c +LV~%?W
B:right outer join: ZeF PwW
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 #Zk6
C:full outer join: %0@Jm)K^
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 Lm"a3Nb
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二、提升 )(b]-
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1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) PoY+Y3
法一:select * into b from a where 1<>1 FSd842O
法二:select top 0 * into b from a 4dv+RRpGOv
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) HE.
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insert into b(a, b, c) select d,e,f from b; +j&4[;8P:
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) CHv~H.kh'
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 z#GZvB/z)
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Hb=4k)-/]
4、说明:子查询(表名1:a 表名2:b) cD
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select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) 0Z8K +,'!
5、说明:显示文章、提交人和最后回复时间 !6\{q
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b #-1 ;
6、说明:外连接查询(表名1:a 表名2:b) N|?"=4Z?
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c |/[?]`
7、说明:在线视图查询(表名1:a ) jTaEaX8+
select * from (SELECT a,b,c FROM a) T where t.a > 1; i}N'WV`!
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ([iMOE[D3
select * from table1 where time between time1 and time2 `Q^G
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select a,b,c, from table1 where a not between 数值1 and 数值2 *Ibl+
9、说明:in 的使用方法 Xa#`VDh
select * from table1 where a [not] in ('值1','值2','值4','值6') g:`V:kbY$
10、说明:两张关联表,删除主表中已经在副表中没有的信息 Wcl@H @
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) tM <6c+
11、说明:四表联查问题: wlKfTJrn&
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 ..... G+[hE|L~y
12、说明:日程安排提前五分钟提醒 Vq2d+
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SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 E(*RtOC<W
13、说明:一条sql 语句搞定数据库分页 QNJ )HNLp
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 _CDUUr
14、说明:前10条记录 ]6Kx0mW
select top 10 * form table1 where 范围 +rfw)c'
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.) a,x-akZWf
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) F]@vmzr
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 _5EM <Ux
(select a from tableA ) except (select a from tableB) except (select a from tableC) yYwZZa1
17、说明:随机取出10条数据 \I1+J9Gl
select top 10 * from tablename order by newid() r ,D
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18、说明:随机选择记录 2G<\Wz
select newid() =o;8xKj
19、说明:删除重复记录 &]3_ .C
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) $(K[W}
20、说明:列出数据库里所有的表名 puA~}6C
select name from sysobjects where type='U' \"{+J
21、说明:列出表里的所有的 xX*I.saK
select name from syscolumns where id=object_id('TableName') iyAeR!`
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 9'faH
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type @v\Osp t=
显示结果: x
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type vender pcs QI'ul e
电脑 A 1 t J
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电脑 A 1 /]=Ih
光盘 B 2 aFGEHZJQ
光盘 A 2 S*VG;m#
手机 B 3 ?%dsY\
手机 C 3 ET;YAa*
23、说明:初始化表table1 Xd@ -
TRUNCATE TABLE table1 d5T M_C
24、说明:选择从10到15的记录 b1JXC=*@
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc p;zV4uSv
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三、技巧 <]xGd!x$
1、1=1,1=2的使用,在SQL语句组合时用的较多 _>+!&_h
"where 1=1" 是表示选择全部 "where 1=2"全部不选, #kjN!S*=
如: N]udZhkn
if @strWhere !='' AE? 0UVI
begin / E}L%OvE
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere +XCLdf}dC
end ad1 I2
else uMKO^D
begin :6~Nq/hZB
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' #N9^C@
end k#X~+}N^
我们可以直接写成 f]Z%,'1^
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere i#]}k
2、收缩数据库 cu*8,*FU
--重建索引 kKL'rT6z
DBCC REINDEX yIy'"BCxM
DBCC INDEXDEFRAG U27YH1OK
--收缩数据和日志 KtTv0[66
DBCC SHRINKDB Q46^i7=
DBCC SHRINKFILE p^QZGu-.W
3、压缩数据库 l\g>@b
dbcc shrinkdatabase(dbname) j}O~6A>|
4、转移数据库给新用户以已存在用户权限 UgI0
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exec sp_change_users_login 'update_one','newname','oldname' ~SUrbRaY>
go z#9Tg"8]
5、检查备份集 3}R}|Ha
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 36"-cGNr{
6、修复数据库 v6=pV4k9
ALTER DATABASE [dvbbs] SET SINGLE_USER M|8vP53=q
GO 4FrP%|%E~
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 0%J0.USkM7
GO 9/2VU<
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ALTER DATABASE [dvbbs] SET MULTI_USER AB(WK9o
GO =2v/f_
7、日志清除 -#@l`kt
SET NOCOUNT ON Z
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DECLARE @LogicalFileName sysname, hK^(Y
@MaxMinutes INT, z5.Uv/n\1
@NewSize INT h|~I'M]*
USE tablename -- 要操作的数据库名 jMUd,j`Opx
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 d8D0 28d
@MaxMinutes = 10, -- Limit on time allowed to wrap log. "[h9hoN
@NewSize = 1 -- 你想设定的日志文件的大小(M) t Sibzl~
-- Setup / initialize cG!\P: re
DECLARE @OriginalSize int R|&jvG=|
SELECT @OriginalSize = size Nini8@d
FROM sysfiles rSu+zS7`X
WHERE name = @LogicalFileName ZtHTl\z
SELECT 'Original Size of ' + db_name() + ' LOG is ' + iWu
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' +
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' K(jo [S
FROM sysfiles k7,
WHERE name = @LogicalFileName PY81MTv0;
CREATE TABLE DummyTrans (|O9L s7N
(DummyColumn char (8000) not null) k-it#'ll{x
DECLARE @Counter INT, \jA#RF.W
@StartTime DATETIME, RW"QUT
@TruncLog VARCHAR(255) 7slpj8
SELECT @StartTime = GETDATE(), Cp"a,% b6u
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' P=3mLz-
DBCC SHRINKFILE (@LogicalFileName, @NewSize) T.d1?
EXEC (@TruncLog) $?P 5A E
-- Wrap the log if necessary. ZZ'5BfI"I%
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired lo!^h]iE !
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ;Aqj$ x
AND (@OriginalSize * 8 /1024) > @NewSize >lPWji'4;
BEGIN -- Outer loop. M'gGoH}B+q
SELECT @Counter = 0 s#Ayl]8r
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) zTBf.A;e7
BEGIN -- update vJ,r}$H3
INSERT DummyTrans VALUES ('Fill Log') I9
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DELETE DummyTrans WwDd62g
SELECT @Counter = @Counter + 1 @T.+:U@S
END XXDLbT'J
EXEC (@TruncLog) XrUc`
END HQkK8'\LP
SELECT 'Final Size of ' + db_name() + ' LOG is ' + nh
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 7q%xF#mK=
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ^sVr#T
FROM sysfiles i0}f@pCB?X
WHERE name = @LogicalFileName E.N@qMn~
DROP TABLE DummyTrans Oa.84a
SET NOCOUNT OFF VW`SqUl
8、说明:更改某个表 WuuF&0?8C
exec sp_changeobjectowner 'tablename','dbo' X 0vcBHh
9、存储更改全部表 g1kYL$ o4
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch %T6
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@OldOwner as NVARCHAR(128), <uG6!P
@NewOwner as NVARCHAR(128) 5Z@0XI
AS )L/0X40<.
DECLARE @Name as NVARCHAR(128) qdnwaJ;&
DECLARE @Owner as NVARCHAR(128) &J?:wC=E
DECLARE @OwnerName as NVARCHAR(128) /hN;\Z[@
DECLARE curObject CURSOR FOR ]?G|:Kx$y%
select 'Name' = name, xm Ns%
'Owner' = user_name(uid) V O\g"Yc
from sysobjects c_4K
where user_name(uid)=@OldOwner rnyXMt.q
order by name do.AesdXaq
OPEN curObject FUVp}>#U
FETCH NEXT FROM curObject INTO @Name, @Owner "5HSCl$r%
WHILE(@@FETCH_STATUS=0) oRZ98?Y\B
BEGIN "wy2u~
if @Owner=@OldOwner vnN0o5
begin [KL-T16
set @OwnerName = @OldOwner + '.' + rtrim(@Name) QHXA?nBX
exec sp_changeobjectowner @OwnerName, @NewOwner d{J@A;da
end +)hxYLk&I
-- select @name,@NewOwner,@OldOwner uf^HDrr<L
FETCH NEXT FROM curObject INTO @Name, @Owner xp? YM35
END ;kzjx%h
close curObject nIr:a|}[
deallocate curObject s*Nb=v.e9
GO bj6;>Ezp3(
10、SQL SERVER中直接循环写入数据 )+Y"4?z~
declare @i int =PF2p'.o
set @i=1 D7r&z?
while @i<30 B:Y F|k}T
begin W{%X1::q$
insert into test (userid) values(@i) Vk> &
set @i=@i+1 g=/!Ry=
end QWc,JCu
小记存储过程中经常用到的本周,本月,本年函数 @O`T|7v
Dateadd(wk,datediff(wk,0,getdate()),-1) ck< `kJ`b
Dateadd(wk,datediff(wk,0,getdate()),6) -7KoR}Ck!
Dateadd(mm,datediff(mm,0,getdate()),0) .?vHoNvo
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 8y']kVg
Dateadd(yy,datediff(yy,0,getdate()),0) ]Cs=EZr
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) D;&\)
上面的SQL代码只是一个时间段 9W0*|!tQ,+
Dateadd(wk,datediff(wk,0,getdate()),-1) dS8ydG2
Dateadd(wk,datediff(wk,0,getdate()),6) g< xE}[gF
就是表示本周时间段. u`ryCZo#g
下面的SQL的条件部分,就是查询时间段在本周范围内的: k;B[wEW@
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ]$uC~b
而在存储过程中 ?b:Pl{?
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) +T&YYO8>5
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Pr:\zI