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。 ['%$vnS5S
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一、基础 Y9SaYSX
1、说明:创建数据库 !q8"Q t
CREATE DATABASE database-name )Y](Mj!D
2、说明:删除数据库 EK%J%NY
drop database dbname VE $Kdo^
3、说明:备份sql server r,r"?}Z
--- 创建 备份数据的 device ty>9i]Y-
USE master u[<ij
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' hN U.y
--- 开始 备份 sqv!,@*q
BACKUP DATABASE pubs TO testBack '}N4SrU$
4、说明:创建新表 oG$OZTc
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) >4^,[IO/
根据已有的表创建新表: $ dR@Q?_{
A:create table tab_new like tab_old (使用旧表创建新表) ]=%oBxWAP
B:create table tab_new as select col1,col2... from tab_old definition only U&'Xsz
5、说明:删除新表 8+n*S$
drop table tabname 0hpU9w}12
6、说明:增加一个列 &-c{
Alter table tabname add column col type tJa*(%Z?f
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。 \hO}3;*&
7、说明:添加主键: Alter table tabname add primary key(col) c $n`=NI
说明:删除主键: Alter table tabname drop primary key(col) .5E6MF
8、说明:创建索引:create [unique] index idxname on tabname(col....) p6&6^v\
删除索引:drop index idxname ']:>Ww.S
注:索引是不可更改的,想更改必须删除重新建。 bCg)PJuB
9、说明:创建视图:create view viewname as select statement rUW/d3y
删除视图:drop view viewname IQ $/|b/
10、说明:几个简单的基本的sql语句 }? :T*CJ
选择:select * from table1 where 范围 g@Z7f y7
插入:insert into table1(field1,field2) values(value1,value2) #ULzh&yO
删除:delete from table1 where 范围 b(Nxk2uv
更新:update table1 set field1=value1 where 范围 peZ'sZ 6
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! *G"}m/j-
排序:select * from table1 order by field1,field2 [desc] Da)H/3ii
总数:select count as totalcount from table1 n.b_fkZNr
求和:select sum(field1) as sumvalue from table1 Fp(-&,L0fc
平均:select avg(field1) as avgvalue from table1 zLSha\X
最大:select max(field1) as maxvalue from table1 VD90JU]X<
最小:select min(field1) as minvalue from table1 m5%E1k$=
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11、说明:几个高级查询运算词 wu;^fL
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A: UNION 运算符 w gkY\Q
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。 5`FPv4
B: EXCEPT 运算符 *s%M!YM
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。 HXP/2&|JY
C: INTERSECT 运算符 u):Nq<X
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。 Z&6*8#wn
注:使用运算词的几个查询结果行必须是一致的。 8FJPw"9
12、说明:使用外连接 vVFT0_
A、left outer join: ;XI=Y"h{%
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。 "3$P<Q\;l;
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c q!as~{!
B:right outer join: C,) e7
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 e8U6D+jY
C:full outer join: -1%AM40j
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 hr?0RPp}
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二、提升 D9r4oRkP*
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) >l =;6QL
法一:select * into b from a where 1<>1 :OD-L)Or
法二:select top 0 * into b from a h/NI5
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) Z!z#+G
insert into b(a, b, c) select d,e,f from b; tKCX0UZ'
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) ,xg(F0q
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ;0nL1R]w(
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. {q/D,Rh8
4、说明:子查询(表名1:a 表名2:b) i{}Q5iy
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) ZJOO*S
5、说明:显示文章、提交人和最后回复时间 )P#xny2
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b Io4Ss1="
6、说明:外连接查询(表名1:a 表名2:b) Y.#:l<
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Z"d21D~h9`
7、说明:在线视图查询(表名1:a ) a/gr1
select * from (SELECT a,b,c FROM a) T where t.a > 1; ,F?O} ijk
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ;tWi4iT+.
select * from table1 where time between time1 and time2 E.4 X,
select a,b,c, from table1 where a not between 数值1 and 数值2 (BZd%!
9、说明:in 的使用方法 4Ep6vm X
select * from table1 where a [not] in ('值1','值2','值4','值6') ,L;%-}#$
10、说明:两张关联表,删除主表中已经在副表中没有的信息 G8@LH
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) X-F:)/$xG
11、说明:四表联查问题: J8@7
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select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... -"x25~k!?F
12、说明:日程安排提前五分钟提醒 %5Zhq>
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 &&TAX
13、说明:一条sql 语句搞定数据库分页 xeKfc}:&z
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 B18?)LA
14、说明:前10条记录 BUU ) Sz
select top 10 * form table1 where 范围 #F:\_!2c
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) 4=ZN4=(_[
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) tREC)+*\
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 S!g0J}.z
(select a from tableA ) except (select a from tableB) except (select a from tableC) f"d4HZD^
17、说明:随机取出10条数据 L r9z~T:ED
select top 10 * from tablename order by newid() ?dQ#%06mn
18、说明:随机选择记录 ?#J;[y\^
select newid() D)J'xG_<O
19、说明:删除重复记录 f=Kt[|%'e
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 10ZL-7D#m
20、说明:列出数据库里所有的表名 mO@Sl(9
select name from sysobjects where type='U' VR vX^w0
21、说明:列出表里的所有的 S!R:a>\
select name from syscolumns where id=object_id('TableName') gFw-P#t
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 m8z414o
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type m$A-'*'
显示结果: ~uw eBp~O
type vender pcs 1*]@1DJt
电脑 A 1 ^e:rRk7 &
电脑 A 1 Y@'ahxF
光盘 B 2 D|"^
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光盘 A 2 H 2UR
手机 B 3 k^Uk=)9
手机 C 3 ~.<}/GP] _
23、说明:初始化表table1 p&cJo<]=LE
TRUNCATE TABLE table1 9I*i/fa
24、说明:选择从10到15的记录 c3|/8
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc cQ`+ A|q
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三、技巧 fXB64MNo
1、1=1,1=2的使用,在SQL语句组合时用的较多 =d1i<iw?-
"where 1=1" 是表示选择全部 "where 1=2"全部不选,
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如: r]O8|#P,Z$
if @strWhere !='' )Ga 3Ji}'
begin X{;3gN
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere (0QYX[(r~o
end B{-+1f4
else }OLBEhGs
begin XFcIBWS
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' k+As#7V
end Jkub|w#QH
我们可以直接写成 ?KXgG'!!
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere & <Jvaf_=
2、收缩数据库 "jAEZ
--重建索引 .>|]Lo(=l
DBCC REINDEX nuLxOd *n
DBCC INDEXDEFRAG uf}Q{@Ab
--收缩数据和日志 rR3(yy0L
DBCC SHRINKDB z9P;HGuZ
DBCC SHRINKFILE }Oh@`xTxt
3、压缩数据库 TF;}NQ
dbcc shrinkdatabase(dbname) a?ii)GGq
4、转移数据库给新用户以已存在用户权限 =U<6TP]{
exec sp_change_users_login 'update_one','newname','oldname' m/>z}d05h
go \:d|'r8OCM
5、检查备份集 h2fTG
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' bx%P-r31
6、修复数据库 t 4tXLI;'
ALTER DATABASE [dvbbs] SET SINGLE_USER 2 NrMse
GO H2D j`0
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ^g*2jH+
GO 4@ =l'Fw
ALTER DATABASE [dvbbs] SET MULTI_USER mp+lN:
GO U{~R39
7、日志清除 "\u_gk{g
SET NOCOUNT ON :Y>M//0
DECLARE @LogicalFileName sysname, U0t~H{-H
@MaxMinutes INT, F!qt#Sw!\
@NewSize INT >aV
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USE tablename -- 要操作的数据库名 H:&|q+K=#
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 >XiTl;UU
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ]aVFWzey
@NewSize = 1 -- 你想设定的日志文件的大小(M) mtu`m6Xix
-- Setup / initialize V;t8v\
DECLARE @OriginalSize int /?Fa<{
SELECT @OriginalSize = size D_4UM#Tw
FROM sysfiles dr8`;$;G*
WHERE name = @LogicalFileName nolLeRE1
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ~i)IY1m"
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + =lqBRut
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' *Mr?}_,X*
FROM sysfiles wa}\bNKQk
WHERE name = @LogicalFileName YQk<1./}I
CREATE TABLE DummyTrans SUQk0 (M
(DummyColumn char (8000) not null) >"q~9b
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DECLARE @Counter INT, :D !}jN/)
@StartTime DATETIME, 7L\kna<
@TruncLog VARCHAR(255) v3{[rK}
SELECT @StartTime = GETDATE(), X6lR?6u%|
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' M<x
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) @fwk
EXEC (@TruncLog) 9x0Ao*D<t
-- Wrap the log if necessary. 60u}iiC@
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired msiftP.
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) k4ijWo{:0
AND (@OriginalSize * 8 /1024) > @NewSize *K1GX
BEGIN -- Outer loop. h%T$m_
SELECT @Counter = 0 yxU??#v|g
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) =7WE
BEGIN -- update 09>lx$
INSERT DummyTrans VALUES ('Fill Log') 3d0Yq
DELETE DummyTrans (e$/@3*
SELECT @Counter = @Counter + 1 (1my9k5C
END @hE$x-TP0
EXEC (@TruncLog) HX]pcX^K
END h#iFp9N
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ZT;:Hxv0N
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 0Zv<]xO
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ;\5^yDv[e
FROM sysfiles &\0V*5tI
WHERE name = @LogicalFileName [rt+KA
DROP TABLE DummyTrans =Nj58 l
SET NOCOUNT OFF 8+7=yN(
8、说明:更改某个表 ve|`I=?2
exec sp_changeobjectowner 'tablename','dbo' .g6DKjy>
9、存储更改全部表 M~1 n#
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch >^Zyls
@OldOwner as NVARCHAR(128), -}O>m}l
@NewOwner as NVARCHAR(128) 0Tm"Zh?B|
AS "/-T{p;.
DECLARE @Name as NVARCHAR(128) TdAHw
@(
DECLARE @Owner as NVARCHAR(128) -UM5&R+o
DECLARE @OwnerName as NVARCHAR(128) @9!,]n
DECLARE curObject CURSOR FOR K{)YnY_E;
select 'Name' = name, E"P5rT
'Owner' = user_name(uid) (y xrK
from sysobjects .RNr^*AQ
where user_name(uid)=@OldOwner *&vySyt
order by name ul',!js?
OPEN curObject aTceGyWzl
FETCH NEXT FROM curObject INTO @Name, @Owner +AT!IZrB2i
WHILE(@@FETCH_STATUS=0) %7$oig\wE
BEGIN YC
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if @Owner=@OldOwner |# zznT"
begin +I?T|Iin
set @OwnerName = @OldOwner + '.' + rtrim(@Name) mne=9/sE"
exec sp_changeobjectowner @OwnerName, @NewOwner n ./onv
end E
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-- select @name,@NewOwner,@OldOwner 2@(Qd3N(
FETCH NEXT FROM curObject INTO @Name, @Owner DfCo=
END tilL7
close curObject 79>8tOuo
deallocate curObject `euk&]/^.)
GO +=y ktf
10、SQL SERVER中直接循环写入数据 btC.EmX
declare @i int 1z\>>N$7B
set @i=1 myj^c>1Iz
while @i<30 U 6y
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begin k-(hJ}N
insert into test (userid) values(@i) z5CWgN
set @i=@i+1 4K@`>Y5g*
end Xj\SJ*
小记存储过程中经常用到的本周,本月,本年函数 $cLtAo^W
Dateadd(wk,datediff(wk,0,getdate()),-1) S;"7d
Dateadd(wk,datediff(wk,0,getdate()),6) .kT5 4U;{
Dateadd(mm,datediff(mm,0,getdate()),0) >o\[?QvP
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) K%: :
Dateadd(yy,datediff(yy,0,getdate()),0) "Iy @PR?>
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) FshQ OFW
上面的SQL代码只是一个时间段 z90=,wd
Dateadd(wk,datediff(wk,0,getdate()),-1) Q-[^!RAK?
Dateadd(wk,datediff(wk,0,getdate()),6) ~lR"3z_Z}
就是表示本周时间段. &pZU