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。 ,apNwkY
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一、基础 *O,H5lwU
1、说明:创建数据库 &?0:v`4Y
CREATE DATABASE database-name )=J5\3O*x
2、说明:删除数据库 qFco3
drop database dbname {`(>O"_[Q
3、说明:备份sql server |Os6V<u"
--- 创建 备份数据的 device ]5}=^
USE master +vW)vS[
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 7Ym(n8
--- 开始 备份 ZrO!L_/
BACKUP DATABASE pubs TO testBack 20b<68h$:
4、说明:创建新表 -`+<{NHv\
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ?WUF!Jk
根据已有的表创建新表: ST5V!jz
A:create table tab_new like tab_old (使用旧表创建新表) iDoDwq!l_
B:create table tab_new as select col1,col2... from tab_old definition only /P:.qtT(
5、说明:删除新表 hB9Ee@
drop table tabname 3*ixlO:qGk
6、说明:增加一个列 8j5<6Cv_
Alter table tabname add column col type R'}95S<
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 J-xS:Ha'l
7、说明:添加主键: Alter table tabname add primary key(col) ~YP Jez
说明:删除主键: Alter table tabname drop primary key(col) t23'x0l
8、说明:创建索引:create [unique] index idxname on tabname(col....) +JRF0T
删除索引:drop index idxname 2 PqS%`XiS
注:索引是不可更改的,想更改必须删除重新建。 #3$\Iu
9、说明:创建视图:create view viewname as select statement i;z{zVR
删除视图:drop view viewname q%(EYM5Y
10、说明:几个简单的基本的sql语句 5| B(\wqG
选择:select * from table1 where 范围 JL=U,Mr6
插入:insert into table1(field1,field2) values(value1,value2)
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删除:delete from table1 where 范围 2I/xJ+
更新:update table1 set field1=value1 where 范围 K+*Q@R D
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! A#8q2n270*
排序:select * from table1 order by field1,field2 [desc] g{IF_ 1
总数:select count as totalcount from table1 uo\ .7[1
求和:select sum(field1) as sumvalue from table1 hRC
平均:select avg(field1) as avgvalue from table1 QaIjLc~W
最大:select max(field1) as maxvalue from table1 m: n`g1
最小:select min(field1) as minvalue from table1 )s_n
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11、说明:几个高级查询运算词 1CU>L[W)
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A: UNION 运算符 /1N6X.Zb
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。 W>_]dPB S/
B: EXCEPT 运算符 j9Ybx#
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。 Snp|!e
C: INTERSECT 运算符 N6K*d` o
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。 PZxAH9 S?
注:使用运算词的几个查询结果行必须是一致的。 zgx&Pte
12、说明:使用外连接 6E(Qx~iL
A、left outer join: ,}oM-B
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。 :NJ_n6E
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 NBl+_/2'w
B:right outer join: FZjHw_pP
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。 [Wd-Zn%
C:full outer join: &'cL%.
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。 \(226^|j
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二、提升 SJD@&m%?[
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) XE^)VLH:
法一:select * into b from a where 1<>1 QXCH(5as
法二:select top 0 * into b from a F,
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) m/#a0~dB
insert into b(a, b, c) select d,e,f from b; "KcA
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) %X#zj"
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ::_i@r
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. d%l{V6
4、说明:子查询(表名1:a 表名2:b) 8DP+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) 8XbA'% o
5、说明:显示文章、提交人和最后回复时间 +`3!I
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b UK9@oCIB
6、说明:外连接查询(表名1:a 表名2:b) ]Q[p@gLd
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c xsWur(> ]
7、说明:在线视图查询(表名1:a ) j
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select * from (SELECT a,b,c FROM a) T where t.a > 1; ECv)v
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 ^vG8#A}]
select * from table1 where time between time1 and time2 [M+f-kl
select a,b,c, from table1 where a not between 数值1 and 数值2 mPq$?gdp
9、说明:in 的使用方法 (O0Urm
select * from table1 where a [not] in ('值1','值2','值4','值6') Q:J^"
10、说明:两张关联表,删除主表中已经在副表中没有的信息 n3J53| %v
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) CI3XzH\IX*
11、说明:四表联查问题: B"%{i-v>**
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 ..... !^Q.VYY
12、说明:日程安排提前五分钟提醒 K~ ;45Z2
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 wEzKqD
13、说明:一条sql 语句搞定数据库分页 hYawU@R
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 6e7{Iy
14、说明:前10条记录 \U@rg4
select top 10 * form table1 where 范围 S_~z-`;h!
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.) 2t $ j
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ;sHN/eF
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 ZE%YXG
(select a from tableA ) except (select a from tableB) except (select a from tableC) TX#m&vh
17、说明:随机取出10条数据 4H@Wc^K
select top 10 * from tablename order by newid() !
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18、说明:随机选择记录 \>Efd
select newid() Qt|c1@J
19、说明:删除重复记录 52o x`t|
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) L/"0ws_
20、说明:列出数据库里所有的表名 $+7`Dy!
select name from sysobjects where type='U' u ElAnrm
21、说明:列出表里的所有的 ?&Pg2]g<
select name from syscolumns where id=object_id('TableName') .L~Nq%g1
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 s|D>-
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type 6 PxW8pn
显示结果: -j&Tc`j_
type vender pcs 7.j[a*^
电脑 A 1 H{t_xL)k.
电脑 A 1 w |l1'
光盘 B 2 8XsguC
光盘 A 2 Ko^c|}mh*!
手机 B 3 ] Eh}L
手机 C 3 &.Zb,r$Y
23、说明:初始化表table1 }MlwC;ot
TRUNCATE TABLE table1 /<rt1&0
24、说明:选择从10到15的记录 j^`hzh3S
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc +S=Rn,
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三、技巧 b=/curl&
1、1=1,1=2的使用,在SQL语句组合时用的较多 ++DG5`
"where 1=1" 是表示选择全部 "where 1=2"全部不选, pFJB'=c
如: #]'rz,E<
if @strWhere !='' ZNx$r]4nF
begin SRSvot};C
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere }mZwd_cK
end 'FYJMIs
else Vrvic4
begin n6k9~ "?
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' )$,"u4
end :f$x Qr4Qz
我们可以直接写成 Ka`=WeJ|
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere )*:`':_a
2、收缩数据库 t>H`X~SR?
--重建索引 (L`j0kPN
DBCC REINDEX }Nb8}(6
DBCC INDEXDEFRAG hxS 6:5Uc
--收缩数据和日志 RW P<B0)
DBCC SHRINKDB : g.46dp4
DBCC SHRINKFILE 0VK-g}"x
3、压缩数据库 ~i.k$XGA
dbcc shrinkdatabase(dbname) ce6__f5?
4、转移数据库给新用户以已存在用户权限 kEd@oC
exec sp_change_users_login 'update_one','newname','oldname' U#1bp}y
go K'h1szW
5、检查备份集 |{@FMxn|q
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' |$7vI&m
6、修复数据库 5?Wto4j
ALTER DATABASE [dvbbs] SET SINGLE_USER $u/E\l
GO rL5z]RY
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ,[A'tUl _
GO ko^\HSXl
ALTER DATABASE [dvbbs] SET MULTI_USER JBnKK
GO lb:/EUd5
7、日志清除 :EHJ\+kejX
SET NOCOUNT ON !u]1dxa
DECLARE @LogicalFileName sysname, (mlzg=szW
@MaxMinutes INT, [2|kl
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@NewSize INT %e@HZ"V
USE tablename -- 要操作的数据库名 b]a@
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 6 K-5g/hL
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 3 R&lqxhg
@NewSize = 1 -- 你想设定的日志文件的大小(M) ;us%/kOR
-- Setup / initialize Nl')l"
DECLARE @OriginalSize int ".dZn6"mI
SELECT @OriginalSize = size ujJI
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FROM sysfiles G/v/+oX
WHERE name = @LogicalFileName [p=*u,-
SELECT 'Original Size of ' + db_name() + ' LOG is ' + YSaJeU>@
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + BYKoel
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' Tz9`uW~Mf
FROM sysfiles 4tx|=;@0
WHERE name = @LogicalFileName qp}Ma8+
CREATE TABLE DummyTrans .6OgO{P:
(DummyColumn char (8000) not null) VAC iVKk
DECLARE @Counter INT, .IJ_jt-^d
@StartTime DATETIME, -rKO
)}
@TruncLog VARCHAR(255) 5Q=P4w!'
SELECT @StartTime = GETDATE(), cJgBI(S5
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' "@9?QI}
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Jxqh)l
EXEC (@TruncLog) Ys!>+nL|
-- Wrap the log if necessary. Od?qz1
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired p!/[K6u
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 7#<c>~
AND (@OriginalSize * 8 /1024) > @NewSize n8hRaNHl2
BEGIN -- Outer loop. B>Wu;a.:L
SELECT @Counter = 0 _
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WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) Y4IGDY*
BEGIN -- update >]%8Zx[
INSERT DummyTrans VALUES ('Fill Log') 0R0{t=VJZ
DELETE DummyTrans Z@gnsPN^r
SELECT @Counter = @Counter + 1 ~}ET?Q7t
END s`Cy
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EXEC (@TruncLog) I-agZag%
END -VZRujl
SELECT 'Final Size of ' + db_name() + ' LOG is ' + VzJ5.mRQ
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + y&_m4Zw"
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' U}$DhA"r"
FROM sysfiles RwVaZJe)l
WHERE name = @LogicalFileName Q o =Kqv
DROP TABLE DummyTrans p*5\+WO>!(
SET NOCOUNT OFF t\v+ogbk)
8、说明:更改某个表 C>Is1i^9
exec sp_changeobjectowner 'tablename','dbo' xug)aE
9、存储更改全部表 dO7;}>F$n
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch vKoP|z=m
@OldOwner as NVARCHAR(128), g+PPW88P;
@NewOwner as NVARCHAR(128) A$.fv5${
AS \C5%\4
DECLARE @Name as NVARCHAR(128) abxDB
DECLARE @Owner as NVARCHAR(128) -6sW6;Q
DECLARE @OwnerName as NVARCHAR(128) htP|3 B
DECLARE curObject CURSOR FOR [Vf}NF
select 'Name' = name, 7~M<cD
'Owner' = user_name(uid) D=RU`?L
from sysobjects -RJE6~>'\
where user_name(uid)=@OldOwner j<"nO(
order by name nW?R"@Zm
OPEN curObject Tp<k<uKD
FETCH NEXT FROM curObject INTO @Name, @Owner l2hG$idC
WHILE(@@FETCH_STATUS=0) )
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BEGIN +CM7C%U
if @Owner=@OldOwner a <X0e>
begin ,)~E>[=+
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ^%y`u1ab
exec sp_changeobjectowner @OwnerName, @NewOwner (bn
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end 5(&xNT-n8
-- select @name,@NewOwner,@OldOwner =neL}Fav56
FETCH NEXT FROM curObject INTO @Name, @Owner -Cid3~mX3
END ix Z)tNz
close curObject o/^;@5\
deallocate curObject +pqM ^3t|y
GO cjULX+h
10、SQL SERVER中直接循环写入数据 `#IcxweA
declare @i int ELa ja87
set @i=1 |Y_
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while @i<30 ;mAhY
begin /48 =UK
insert into test (userid) values(@i) &~5=K
set @i=@i+1 9>,Qgp,w
end GO5 ~!g
小记存储过程中经常用到的本周,本月,本年函数 ;_<)JqUh
Dateadd(wk,datediff(wk,0,getdate()),-1) <M[U#Q~?~e
Dateadd(wk,datediff(wk,0,getdate()),6) qX>Q+_^
Dateadd(mm,datediff(mm,0,getdate()),0) )WR_
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Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) G5]1s
Dateadd(yy,datediff(yy,0,getdate()),0) 8V4V3^_xs
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) kRIB<@{
上面的SQL代码只是一个时间段 "EftN5?/
Dateadd(wk,datediff(wk,0,getdate()),-1) aW5~Be$
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Dateadd(wk,datediff(wk,0,getdate()),6) Y9}8M27vQG
就是表示本周时间段. rPq<Xb\
下面的SQL的条件部分,就是查询时间段在本周范围内的: BH :
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) S-E++f9D~
而在存储过程中 ]" x\=A
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) XKLF8~y8A
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) :7;[`bm(G