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。 E>r7A5Uo
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一、基础 5e?<x>e
1、说明:创建数据库 j^hLn>
CREATE DATABASE database-name 0fqycGSmU
2、说明:删除数据库 'C>sYSL
drop database dbname 8 0o'=E}"
3、说明:备份sql server [1z.JfC :S
--- 创建 备份数据的 device :"@-Bcln
USE master 8L6b:$Y3@C
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' kN#3HI]8
--- 开始 备份 Zzb?Nbf
BACKUP DATABASE pubs TO testBack (zk/>Ou
4、说明:创建新表 ovi^bNQ
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) |goK@<
根据已有的表创建新表: /f AAQ7
A:create table tab_new like tab_old (使用旧表创建新表) $>+g)
B:create table tab_new as select col1,col2... from tab_old definition only kZi/2UA5Z
5、说明:删除新表 dB:c2
drop table tabname iHvWJ<"jR
6、说明:增加一个列 UG}2q:ST
Alter table tabname add column col type 0y+i?y
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注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 2n-kJl`: O
7、说明:添加主键: Alter table tabname add primary key(col) h[<l2fy
说明:删除主键: Alter table tabname drop primary key(col) GY^;$ ?
8、说明:创建索引:create [unique] index idxname on tabname(col....) nI1(2a1
删除索引:drop index idxname $3%+N|L
注:索引是不可更改的,想更改必须删除重新建。 hMV>5Y[s
9、说明:创建视图:create view viewname as select statement +F2X2e)g"
删除视图:drop view viewname MpIiHKQ
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10、说明:几个简单的基本的sql语句 E\p"%
选择:select * from table1 where 范围 =+q\Jh
插入:insert into table1(field1,field2) values(value1,value2) j5]ul!ji
删除:delete from table1 where 范围 Y4_xV&
更新:update table1 set field1=value1 where 范围 ,*?[Rg0]+
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ooC9a>X
排序:select * from table1 order by field1,field2 [desc] m^,VEV>
总数:select count as totalcount from table1 TZ!@IBu
求和:select sum(field1) as sumvalue from table1 S_;r!.
平均:select avg(field1) as avgvalue from table1 8lA,3'z
最大:select max(field1) as maxvalue from table1 W,_2JqQp
最小:select min(field1) as minvalue from table1 <td]k%*+
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11、说明:几个高级查询运算词 -~X[j2
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A: UNION 运算符 tCar:p4$
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。 #3'M>SaoH
B: EXCEPT 运算符 D_)/.m
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。 ED>a'y$f
C: INTERSECT 运算符 hhFO,
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 .0~uM!3y
注:使用运算词的几个查询结果行必须是一致的。 )}t't"
12、说明:使用外连接 L'
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A、left outer join:
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左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 ;K%/sIIke
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Q;A\M
B:right outer join: {t!7r_hj
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 %/5Wj_|p
C:full outer join: _mwt{D2r}
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 M CP GDr
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二、提升
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1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) "Wr[DqFd
法一:select * into b from a where 1<>1 vUOl@UQ5
法二:select top 0 * into b from a 4z9lk^#"X
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) M]/DKo
insert into b(a, b, c) select d,e,f from b; a ~W
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) U%[ye0@:
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 lBAu@M
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. nAAv42j[
4、说明:子查询(表名1:a 表名2:b) e?*Teb?R
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) HXztEEK6
5、说明:显示文章、提交人和最后回复时间 bS954d/
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b %\n|2*r
6、说明:外连接查询(表名1:a 表名2:b) ffBd
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c AQT_s9"0
7、说明:在线视图查询(表名1:a ) 4l68+
select * from (SELECT a,b,c FROM a) T where t.a > 1; M}f(-,9
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 CjP<'0gT
select * from table1 where time between time1 and time2 r@bh,U$
select a,b,c, from table1 where a not between 数值1 and 数值2 T#*H
9、说明:in 的使用方法 22U`1AD3U
select * from table1 where a [not] in ('值1','值2','值4','值6') S6a\KtVa
10、说明:两张关联表,删除主表中已经在副表中没有的信息 (Cfb8\~
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) QCE7VV1Rw
11、说明:四表联查问题: 0Oc?:R'$
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 ..... $(]nl%<Q
12、说明:日程安排提前五分钟提醒 X{OWDy
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 !2Z"Lm
13、说明:一条sql 语句搞定数据库分页 85;bJfY
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 SgehOu
14、说明:前10条记录 )|^8`f
select top 10 * form table1 where 范围 /kg#i&bP~
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) u*rP8GuS
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) '[%#70*
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 Ke?,AWfG
(select a from tableA ) except (select a from tableB) except (select a from tableC) w^$C\bCbh
17、说明:随机取出10条数据 j%^4
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select top 10 * from tablename order by newid() 79exZ7|
18、说明:随机选择记录 ahy6a,)K~
select newid() 8T6NG!/
19、说明:删除重复记录 hh&$xlO)(v
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) o ]z#~^w
20、说明:列出数据库里所有的表名 }u=Oi@~
select name from sysobjects where type='U' #kq!{5,
21、说明:列出表里的所有的 x\8|A
select name from syscolumns where id=object_id('TableName') 3}F>t{FDk
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 El;"7Qn
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type <r$h =hM
显示结果: g= Vu'p 3u
type vender pcs $Th)z}A}EA
电脑 A 1 $T^q>v2u
电脑 A 1 &ah%^Z4um
光盘 B 2 oW6Hufu+o
光盘 A 2 t"q'"FX
手机 B 3 vc&+qI+I3
手机 C 3 ?_Z-}f
23、说明:初始化表table1 m m`#v
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TRUNCATE TABLE table1 r9'[7b1l
24、说明:选择从10到15的记录 M(LIF^'U:m
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc `Hlf.>b1
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三、技巧 ce}A!v
1、1=1,1=2的使用,在SQL语句组合时用的较多 10*Tk 8
"where 1=1" 是表示选择全部 "where 1=2"全部不选, _#6Qf
如: h\w;SDwOk
if @strWhere !='' ,)#rD9ZnC
begin )`f-qTe
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ~ILv*v@m
end >19s:+
else \\#D!q*
begin 5P"R'/[PA_
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' kaB|+U9^
end o
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我们可以直接写成 iBSg`"S^]C
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ]h(Iun
2、收缩数据库 Td'(RV
--重建索引 }RI_k&;
DBCC REINDEX rxu_Ssd@"
DBCC INDEXDEFRAG C1=&Vm>g+
--收缩数据和日志 jgIG";:Q
DBCC SHRINKDB m{ !$_z8:
DBCC SHRINKFILE zdRVAcrwQ
3、压缩数据库 tJrGRlB>
dbcc shrinkdatabase(dbname) 4=Ru{ewRV
4、转移数据库给新用户以已存在用户权限 xL"J?Gy
exec sp_change_users_login 'update_one','newname','oldname' ~44u_^a
go az0=jou<Zl
5、检查备份集 aH'fAX0bF
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 9]oT/ooM
6、修复数据库 BoYY^ih
ALTER DATABASE [dvbbs] SET SINGLE_USER v7wyQx+Q
GO 8VMA~7^
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK \]]K{DO
GO |xFA}
ALTER DATABASE [dvbbs] SET MULTI_USER ~rdS#f&R2
GO ZF[W<Q
7、日志清除 w
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SET NOCOUNT ON `D~oY=
DECLARE @LogicalFileName sysname,
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@MaxMinutes INT, y
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@NewSize INT -6kX?sNl)X
USE tablename -- 要操作的数据库名 SefhOh^,V
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Kgr<OL}V J
@MaxMinutes = 10, -- Limit on time allowed to wrap log. *pa hZiO
@NewSize = 1 -- 你想设定的日志文件的大小(M) :p/=KI_
-- Setup / initialize }
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DECLARE @OriginalSize int oOpEpQ}}q
SELECT @OriginalSize = size lt6wmCe
FROM sysfiles ue@/o,C>
WHERE name = @LogicalFileName 9S@x
SELECT 'Original Size of ' + db_name() + ' LOG is ' + #&Tm%CvB
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + /g{*px|
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ="& GU%$
FROM sysfiles 5.{=Op!
WHERE name = @LogicalFileName Sc>mw
CREATE TABLE DummyTrans 'sUOi7U
(DummyColumn char (8000) not null) IeYNTk&<
DECLARE @Counter INT, e&VC}%m
@StartTime DATETIME, l%"DeRp,/
@TruncLog VARCHAR(255) hHJvLs>^
SELECT @StartTime = GETDATE(), p7Wt(A
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' }vZf&ib-
DBCC SHRINKFILE (@LogicalFileName, @NewSize) )Y)_T&O
EXEC (@TruncLog) q=5aHH% |
-- Wrap the log if necessary. +\Jo^\
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired )Su>8f[?e
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) `D[O\ VE
AND (@OriginalSize * 8 /1024) > @NewSize ~F'6k&A^q
BEGIN -- Outer loop. m_/Ut
SELECT @Counter = 0 ,FzkGB#
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) r4SwvxhG
BEGIN -- update N)g _LL>^
INSERT DummyTrans VALUES ('Fill Log') $J4\jIipL
DELETE DummyTrans w gS'/
SELECT @Counter = @Counter + 1 zFm`e:td
END uE')<fVX(
EXEC (@TruncLog) &!X<F,
END HAK,z0/
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ^t4^gcoZ4Z
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ';FJs&=I
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' wz`% (\
FROM sysfiles @`L;_S+
WHERE name = @LogicalFileName V*\hGNV
DROP TABLE DummyTrans S}JOS}\^j
SET NOCOUNT OFF . J O3#
8、说明:更改某个表 2.%)OC!q&5
exec sp_changeobjectowner 'tablename','dbo' tJ;qZyy(
9、存储更改全部表 zni9
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch pV ^+X}
@OldOwner as NVARCHAR(128), ZMgsuzg
@NewOwner as NVARCHAR(128) hO8xH +;
AS 1<_][u@
DECLARE @Name as NVARCHAR(128) j_so s%-
DECLARE @Owner as NVARCHAR(128) 62R";# K
DECLARE @OwnerName as NVARCHAR(128) K{DC{yLu
DECLARE curObject CURSOR FOR N=1ue`i
select 'Name' = name, ZEI)U,
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'Owner' = user_name(uid) C5dM`_3L
from sysobjects E42)93~C
where user_name(uid)=@OldOwner Hj{.{V
order by name 8*0QVFn$
OPEN curObject Bp7p X
FETCH NEXT FROM curObject INTO @Name, @Owner Li5&^RAo|J
WHILE(@@FETCH_STATUS=0) USyc D`
BEGIN )v;O2z
if @Owner=@OldOwner n5d8^c! 2
begin `YqtI/-w
set @OwnerName = @OldOwner + '.' + rtrim(@Name) yk4@@kHW
exec sp_changeobjectowner @OwnerName, @NewOwner c46-8z$
end Qa=Y?=Za
-- select @name,@NewOwner,@OldOwner 7zw0g~+
FETCH NEXT FROM curObject INTO @Name, @Owner /";tkad^
END >b2!&dm
close curObject e1W9"&4>G{
deallocate curObject Q ")Xg:
GO >IaGa!4
10、SQL SERVER中直接循环写入数据 oIick
declare @i int BQPmo1B
set @i=1 gaz7u8$A=
while @i<30 }2;P`s
begin b69nj
insert into test (userid) values(@i) G"FO%3&|
set @i=@i+1 O +o)z6(
end F@Sk=l(
小记存储过程中经常用到的本周,本月,本年函数 z<5 5[~3
Dateadd(wk,datediff(wk,0,getdate()),-1) F&wAre<
Dateadd(wk,datediff(wk,0,getdate()),6) mh}D[K=~%
Dateadd(mm,datediff(mm,0,getdate()),0) LH4#p%Pb%
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) nu\AEFT
Dateadd(yy,datediff(yy,0,getdate()),0) y-+W
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 7/~=[#]*
上面的SQL代码只是一个时间段 iG54 +]
Dateadd(wk,datediff(wk,0,getdate()),-1) *?t$Q|2Xr
Dateadd(wk,datediff(wk,0,getdate()),6) b+qd'
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就是表示本周时间段. DehjV6t
下面的SQL的条件部分,就是查询时间段在本周范围内的: ^~V2xCu!
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Ds(Z.
而在存储过程中 /.e7#-+?
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) As46:<!2
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) <w^u^)iLy1