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。 4(TR'_X(
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一、基础 ObSRd$M
1、说明:创建数据库 aLO'.5
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CREATE DATABASE database-name Gk]6WLi
2、说明:删除数据库 o>o! -uf
drop database dbname ?+?`Jso(
3、说明:备份sql server y28 e=i
--- 创建 备份数据的 device X%
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USE master !+T29QYK8
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' ~'#,*kA:6
--- 开始 备份 N_R(i3c6U!
BACKUP DATABASE pubs TO testBack Jq_AR!} %
4、说明:创建新表 FwqaWEk
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) <L+y
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根据已有的表创建新表: IRIYj(J
A:create table tab_new like tab_old (使用旧表创建新表) LyG&FOf?
B:create table tab_new as select col1,col2... from tab_old definition only rvp#[RAaS}
5、说明:删除新表 [xH Hm5$
drop table tabname I:edLg1T
6、说明:增加一个列 $n* wS,
Alter table tabname add column col type =jkiM_<h
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 Qgxpq{y
7、说明:添加主键: Alter table tabname add primary key(col) _7b' i6-
说明:删除主键: Alter table tabname drop primary key(col) \&b1%Asyz
8、说明:创建索引:create [unique] index idxname on tabname(col....) Sq[LwJ
删除索引:drop index idxname cA{7*=G?
注:索引是不可更改的,想更改必须删除重新建。 J1"16Uu
9、说明:创建视图:create view viewname as select statement wAF<_NG#
删除视图:drop view viewname WnL7 A:sZ
10、说明:几个简单的基本的sql语句 Zce/&
选择:select * from table1 where 范围 l'twy$V4|~
插入:insert into table1(field1,field2) values(value1,value2) f8S! FGiNc
删除:delete from table1 where 范围 ;%!]C0?
更新:update table1 set field1=value1 where 范围 $HP<C>^Z8
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! VRD:PVz
排序:select * from table1 order by field1,field2 [desc] z~Is
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总数:select count as totalcount from table1 |:,i
求和:select sum(field1) as sumvalue from table1 fzjAP7 y
平均:select avg(field1) as avgvalue from table1 4^_'LiX3[
最大:select max(field1) as maxvalue from table1 9qI#vHA
最小:select min(field1) as minvalue from table1 P~M<OUg
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11、说明:几个高级查询运算词 LGq
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A: UNION 运算符 {8T/;K@
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。 AYGe`{
B: EXCEPT 运算符 Mq52B_
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。 EGxCNB
C: INTERSECT 运算符 bE6bx6=u
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。 'J_`CS
注:使用运算词的几个查询结果行必须是一致的。 odhcU5
12、说明:使用外连接 wf2v9.;X:<
A、left outer join: &NH[b1NMr
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。 >!WH%J
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 Dy|)u1?
B:right outer join: 'f-8P
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。 uYCWsw/
C:full outer join: :N64FR#
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。 f f5 e]^,
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二、提升 i)=
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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) v@QfxV2
法一:select * into b from a where 1<>1 HcCT=x7:
法二:select top 0 * into b from a Ot;)zft
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) Dbw{E:pq
insert into b(a, b, c) select d,e,f from b; D\^\_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) `rb}"V+
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 Zmz $
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 7UsU03
4、说明:子查询(表名1:a 表名2:b) )8%m|v#W
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) nd~O*-uYg
5、说明:显示文章、提交人和最后回复时间 S#*aB2ZS
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b M`p[ Zq
6、说明:外连接查询(表名1:a 表名2:b) w\y)
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c <op|yh3Jkk
7、说明:在线视图查询(表名1:a ) b=XXp`h~a
select * from (SELECT a,b,c FROM a) T where t.a > 1; qaG8:
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 dy3fZ(=q^
select * from table1 where time between time1 and time2 gN.n_!
select a,b,c, from table1 where a not between 数值1 and 数值2 c'
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9、说明:in 的使用方法 om2)Cd9~7
select * from table1 where a [not] in ('值1','值2','值4','值6') E7 P'}
10、说明:两张关联表,删除主表中已经在副表中没有的信息 d~#:t~
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delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ;k
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11、说明:四表联查问题: A,4Z{f83
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 ..... -+y3~^EYm,
12、说明:日程安排提前五分钟提醒 22@w:
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 AmB*4p5b
13、说明:一条sql 语句搞定数据库分页 WSbD."p<
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 [oOV@GE
14、说明:前10条记录 9QHV%%
select top 10 * form table1 where 范围 N#GMvU#R
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.) 5#~E[dr
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) )6{,y{5!
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 x9\]C'*sO
(select a from tableA ) except (select a from tableB) except (select a from tableC)
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17、说明:随机取出10条数据 H1r8n$h
select top 10 * from tablename order by newid() +}iuTqu5
18、说明:随机选择记录 ;s?,QvE{r#
select newid() tHV+#3h
19、说明:删除重复记录 yOO@v6jO)
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ,"5][RsOn
20、说明:列出数据库里所有的表名 1*?L>@Wdy
select name from sysobjects where type='U' LAY~hF"
21、说明:列出表里的所有的 &M7AM"9
select name from syscolumns where id=object_id('TableName') v)JS4KS
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 !q 9PO
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type RV),E:?
显示结果: B-h@\y
type vender pcs B^Hhrz!
电脑 A 1 ny1Dg$ui2
电脑 A 1 ]h'*L`
光盘 B 2 @3`Pq2<
光盘 A 2 %xdyGAl:
手机 B 3 pkc*toW
手机 C 3 g`dAj4B
23、说明:初始化表table1 W1ql[DqE{
TRUNCATE TABLE table1 10CRgrZ
24、说明:选择从10到15的记录 H18pVh
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc t**MthnW
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三、技巧 6|QIzs<Z-X
1、1=1,1=2的使用,在SQL语句组合时用的较多 AbIYdFX B
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Cy6%f? j
如: %7
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if @strWhere !='' X'p%K/-m
begin NUh+ &M
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere UZ!It>
end 03gYl0B
else *BKIA
begin VjJ}q*/3e
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' |eK^Yhym
end 84/#,X!=s
我们可以直接写成 l:*.0Tj
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere -'T^gEd)c
2、收缩数据库 h059 DiH
--重建索引 >dnDN3x
DBCC REINDEX uOPLJ?%
DBCC INDEXDEFRAG Bw>)gSB5$k
--收缩数据和日志 ?8YbTn1f)
DBCC SHRINKDB as"@E>a
DBCC SHRINKFILE @b{$s
3、压缩数据库 C0W-}H
dbcc shrinkdatabase(dbname) E.G]T#wt0
4、转移数据库给新用户以已存在用户权限 d$y?py
exec sp_change_users_login 'update_one','newname','oldname' {?Cm
go MP~+@0cv
5、检查备份集 bJ]blnH
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' B1TWOl?d{
6、修复数据库 $V;0z~&!'
ALTER DATABASE [dvbbs] SET SINGLE_USER _Zus4&'
GO M=4`^.Ocm
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK T!-ly7-`
GO 3*N0oc^m
ALTER DATABASE [dvbbs] SET MULTI_USER 3x>Y
GO i4mP*RwC
7、日志清除 JtxitF2
SET NOCOUNT ON ucFfxar"
DECLARE @LogicalFileName sysname, =lL)g"xX
@MaxMinutes INT, Tr,
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@NewSize INT n@J>,K_B
USE tablename -- 要操作的数据库名 's$/-AV
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 F!P,%JmI<
@MaxMinutes = 10, -- Limit on time allowed to wrap log. *hh iIiog+
@NewSize = 1 -- 你想设定的日志文件的大小(M) j-wKm_M#jX
-- Setup / initialize ppnl bL^*
DECLARE @OriginalSize int lS?#(}a1)
SELECT @OriginalSize = size `:W }yo<F
FROM sysfiles 8Fv4\dr
WHERE name = @LogicalFileName gdS@NUM
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ($t;Xab
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + XRi37|p
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' eg"A?S
FROM sysfiles [X ]XH
WHERE name = @LogicalFileName KxDfPd+j[
CREATE TABLE DummyTrans '?T<o
(DummyColumn char (8000) not null) g#o9[su
DECLARE @Counter INT, 6
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@StartTime DATETIME, !J[! i"e
@TruncLog VARCHAR(255) 3\K;y>NK
SELECT @StartTime = GETDATE(), e8{!Kjiz
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' oE)xL%*
DBCC SHRINKFILE (@LogicalFileName, @NewSize)
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EXEC (@TruncLog) '`j MNKn\
-- Wrap the log if necessary. OV`li#H
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired J:G{
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) W&7(
AND (@OriginalSize * 8 /1024) > @NewSize goc; .~?
BEGIN -- Outer loop. eQ<GNvm
SELECT @Counter = 0 .M0pb^M
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) +@~e9ZG%a
BEGIN -- update dw%g9DT
INSERT DummyTrans VALUES ('Fill Log') @#yl_r%
DELETE DummyTrans ;WG%)^e
SELECT @Counter = @Counter + 1 L$ZsNs+
END [ ^gb6W9Y
EXEC (@TruncLog) &;U
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END p,14'HS%@
SELECT 'Final Size of ' + db_name() + ' LOG is ' + I7W?}bR*6
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + m,&2s-v
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 1^2]~R9,9
FROM sysfiles J7@Q;gcl:
WHERE name = @LogicalFileName d3NER} f4V
DROP TABLE DummyTrans %2'Y@AX`
SET NOCOUNT OFF zpg512\y
8、说明:更改某个表 {FR+a**
exec sp_changeobjectowner 'tablename','dbo' 9Dd`x7$a
9、存储更改全部表 g|M>C:ZT
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch q siV
@OldOwner as NVARCHAR(128), z&z5EtFUTh
@NewOwner as NVARCHAR(128) ,r;E[k@
AS
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DECLARE @Name as NVARCHAR(128) K4b2)8
DECLARE @Owner as NVARCHAR(128) g`4WisL1n
DECLARE @OwnerName as NVARCHAR(128) d w'P =8d
DECLARE curObject CURSOR FOR \_7'f
select 'Name' = name, kArF Gb2c
'Owner' = user_name(uid) O;.DQ
from sysobjects "
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where user_name(uid)=@OldOwner B5[As8Sa
order by name M-(,*6Q
OPEN curObject 1jd.tup
FETCH NEXT FROM curObject INTO @Name, @Owner %yK- Q,'O
WHILE(@@FETCH_STATUS=0) _)6r@fZ.p
BEGIN @eYD@!
if @Owner=@OldOwner f6m
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begin AR c
set @OwnerName = @OldOwner + '.' + rtrim(@Name) %!R\-Vej
exec sp_changeobjectowner @OwnerName, @NewOwner
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end _~;K]
-- select @name,@NewOwner,@OldOwner a!.Y@o5Ku
FETCH NEXT FROM curObject INTO @Name, @Owner k=X)axt1
END z6fY_LL
close curObject yF-`f
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deallocate curObject #
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GO pL: r\Y:R
10、SQL SERVER中直接循环写入数据 SPnW8
declare @i int 0>
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set @i=1 9{%/I
while @i<30 gp+@+i>b+[
begin ;X+cS,h
insert into test (userid) values(@i) lU`t~|>r+
set @i=@i+1 ,M
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end p{&o{+c
小记存储过程中经常用到的本周,本月,本年函数 ]+>Kl>@
Dateadd(wk,datediff(wk,0,getdate()),-1) 0CI\Yd=
Dateadd(wk,datediff(wk,0,getdate()),6) xu@xP5GB^
Dateadd(mm,datediff(mm,0,getdate()),0) WA5.qw
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) wdIJ?\/763
Dateadd(yy,datediff(yy,0,getdate()),0) l0E]#ra"
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) I0G[K~gb
上面的SQL代码只是一个时间段 \)W Z D
Dateadd(wk,datediff(wk,0,getdate()),-1) 4D6LP*
Dateadd(wk,datediff(wk,0,getdate()),6) kJ)Z{hy
就是表示本周时间段. 0Y8Cz /$
下面的SQL的条件部分,就是查询时间段在本周范围内的: CDT;AdRw7
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) #<es>~0!
而在存储过程中 [S0wwWU |0
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) P.djR)YI
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) O2/_$i[F