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。 -\?-
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一、基础 (Fzy8
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1、说明:创建数据库 "E2 0Y"[h
CREATE DATABASE database-name lY
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2、说明:删除数据库 4joE"H6
drop database dbname )x/#sW%)
3、说明:备份sql server gp`@dn';
--- 创建 备份数据的 device X<;.
USE master ~-7/9$ay5
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' G:$kGzhJ
--- 开始 备份 C
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BACKUP DATABASE pubs TO testBack ,6g{-r-2
4、说明:创建新表 'M"z3j]m-,
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ?(=|!`IoO
根据已有的表创建新表: T/P\j0hR
A:create table tab_new like tab_old (使用旧表创建新表) I8J>>H'#A
B:create table tab_new as select col1,col2... from tab_old definition only (rBsh6@)
5、说明:删除新表 ~+4lmslR
drop table tabname 9t\14tVwx
6、说明:增加一个列 ,ZJ}X 9$<
Alter table tabname add column col type U U_0@V<
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 Ln,<|,fZN
7、说明:添加主键: Alter table tabname add primary key(col) ~q566k!Ll!
说明:删除主键: Alter table tabname drop primary key(col) 3?FY?Q[
8、说明:创建索引:create [unique] index idxname on tabname(col....) ,Lp"Ia
删除索引:drop index idxname Wu$ryX
注:索引是不可更改的,想更改必须删除重新建。 '/HShS!d
9、说明:创建视图:create view viewname as select statement fL2P6N@
删除视图:drop view viewname f<bB= 9J
10、说明:几个简单的基本的sql语句 )m7%cyfC
选择:select * from table1 where 范围 WMtFXkf6"
插入:insert into table1(field1,field2) values(value1,value2) Ro2V-6/
删除:delete from table1 where 范围 -"nkC
更新:update table1 set field1=value1 where 范围 .Bl:hk\
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! lF(v<drkB
排序:select * from table1 order by field1,field2 [desc] ck]I?
总数:select count as totalcount from table1 y{mt *VA4
求和:select sum(field1) as sumvalue from table1 e#HPU
平均:select avg(field1) as avgvalue from table1 AJi+JO-
最大:select max(field1) as maxvalue from table1 t!rrYBSCr
最小:select min(field1) as minvalue from table1 (9%?ik
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11、说明:几个高级查询运算词 ^ou)c/68aQ
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A: UNION 运算符 Iz+%wAZ|B6
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。 ]}/Rl}_
B: EXCEPT 运算符 PzKTEYJL
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。 %^lD
C: INTERSECT 运算符 FA-cTF[,(
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。 :&
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注:使用运算词的几个查询结果行必须是一致的。 JR`$t~0t
12、说明:使用外连接 %_s)Gw&sq
A、left outer join: UeFJ5n'x:
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 2EM6k|l5
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ZOPK
B:right outer join: ?=Ceo#Er
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 6inAnC@I
C:full outer join: ~`BkCTT
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 @*vVc`;
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二、提升 }d}sC\>U
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) >U*p[ FGW
法一:select * into b from a where 1<>1 If'2
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法二:select top 0 * into b from a &mtt,]6C_
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ShC$ue?Q
insert into b(a, b, c) select d,e,f from b; P0>2}/;o
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) (^iF)z
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 I;JV-jDM
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. \9`E17i
4、说明:子查询(表名1:a 表名2:b) H'#06zP>5
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) MkMDI)Y|
5、说明:显示文章、提交人和最后回复时间 |
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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 -B-G$ii
6、说明:外连接查询(表名1:a 表名2:b) tx
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 5B)&;[
7、说明:在线视图查询(表名1:a ) X>`03?L
select * from (SELECT a,b,c FROM a) T where t.a > 1; !{+CzUo@
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 dz+!yE\f$
select * from table1 where time between time1 and time2 g(i6Uj~)
select a,b,c, from table1 where a not between 数值1 and 数值2 giu{,gS0?M
9、说明:in 的使用方法 0'6ai=W
select * from table1 where a [not] in ('值1','值2','值4','值6') iw MxTty
10、说明:两张关联表,删除主表中已经在副表中没有的信息 j"6|$Ze8
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) d@ 8M_
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11、说明:四表联查问题: Q(-&}cY
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 ..... P6kDtUXF
12、说明:日程安排提前五分钟提醒 3);P!W4>
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ',g%L_8Sq
13、说明:一条sql 语句搞定数据库分页 (<>??(VM
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 {Ni]S$7
14、说明:前10条记录 )rP,+ B?W
select top 10 * form table1 where 范围 Nzgi)xX0HX
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.) ^k7I+A
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) o@gceZuk
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 fx+_;y
(select a from tableA ) except (select a from tableB) except (select a from tableC) )B
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17、说明:随机取出10条数据 RK-bsf
select top 10 * from tablename order by newid() DgcS@N
18、说明:随机选择记录 >ye.rRZd`
select newid() >k`qPpf&
19、说明:删除重复记录 ^vM6_=g2E%
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) }*rS g .
20、说明:列出数据库里所有的表名 Htr]_<@
select name from sysobjects where type='U' eY#^vB
21、说明:列出表里的所有的
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select name from syscolumns where id=object_id('TableName') d #1&"(
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。 @"NP`#
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 'z,kxra|n
显示结果: %dnpO|L
type vender pcs ?XdvZf $
电脑 A 1 `},:dDHI
电脑 A 1 {1Cnrjw
光盘 B 2
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光盘 A 2 Dks n
手机 B 3 UfPB-EFl$D
手机 C 3 @`
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23、说明:初始化表table1 ,N:^4A
TRUNCATE TABLE table1 ,nL~?h-Zh
24、说明:选择从10到15的记录 #!z-)[S.+
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 8tSY|ME
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三、技巧 Y>aVnixx<
1、1=1,1=2的使用,在SQL语句组合时用的较多 ^A&{g.0
"where 1=1" 是表示选择全部 "where 1=2"全部不选, r3?8nQ$
如: Z*w({k7]
if @strWhere !='' C ibfuR
begin tH;9"z#
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere |-vyhr0
end eCKm4l'BZ
else {J1rjrPo
begin
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' [dLc+h1{B
end V^FM-bg%9
我们可以直接写成 ='D%c^;O8'
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 4w%hvJ
2、收缩数据库 ;p*L(8<YI
--重建索引 *IbDA
DBCC REINDEX gmu.8
DBCC INDEXDEFRAG 4N=,9
--收缩数据和日志 ,B;mG]_
DBCC SHRINKDB mQ}\ptdfV
DBCC SHRINKFILE 2&'uO'K
3、压缩数据库 } %0w25
dbcc shrinkdatabase(dbname) yg}L,JJU<
4、转移数据库给新用户以已存在用户权限
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exec sp_change_users_login 'update_one','newname','oldname' !-qk1+<h
go jS3@Z?x?*
5、检查备份集 F !v01]O
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Us "G X_
6、修复数据库 u*iqwm.
ALTER DATABASE [dvbbs] SET SINGLE_USER ~7}no}7
GO (*eX'^Q)d
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK |:(B I5&S
GO :W&klUU"
ALTER DATABASE [dvbbs] SET MULTI_USER :.H@tBi*E
GO (.oDxs()I
7、日志清除 jyg>'"W
SET NOCOUNT ON E.$//P n|1
DECLARE @LogicalFileName sysname, 056yhB
@MaxMinutes INT, .-s!} P"
@NewSize INT /-<]v3J
USE tablename -- 要操作的数据库名 =#TQXm']Gi
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ocW`sE?EED
@MaxMinutes = 10, -- Limit on time allowed to wrap log. Rbm+V{EF&
@NewSize = 1 -- 你想设定的日志文件的大小(M) p(4Ek"
-- Setup / initialize Np9Pae'
DECLARE @OriginalSize int b2F1^]p
SELECT @OriginalSize = size ) tV]h#4
FROM sysfiles &e[Lb:Uk)
WHERE name = @LogicalFileName VasQ/
SELECT 'Original Size of ' + db_name() + ' LOG is ' + +f]I7e:qp
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ZMyd+C_P2
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' $3#oA.~R/
FROM sysfiles qy\SOAh
WHERE name = @LogicalFileName :i?c
CREATE TABLE DummyTrans /$vX1T
(DummyColumn char (8000) not null) <N80MUL|
DECLARE @Counter INT, jq/{|<0
@StartTime DATETIME, ^kB9
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@TruncLog VARCHAR(255) Ej VB\6,
SELECT @StartTime = GETDATE(), 8r\xQr'8h
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' )[sSCt]
DBCC SHRINKFILE (@LogicalFileName, @NewSize) -IV-"-6(
EXEC (@TruncLog) &E
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-- Wrap the log if necessary.
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired BYS>"
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) W\DJXM]b
AND (@OriginalSize * 8 /1024) > @NewSize \v9<L'NP)
BEGIN -- Outer loop. 10/3 -)+
SELECT @Counter = 0 B T{({3
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) z#&qWO
BEGIN -- update Sag\wKV8
INSERT DummyTrans VALUES ('Fill Log') 483vFLnF
DELETE DummyTrans e''Wm.>g(+
SELECT @Counter = @Counter + 1 }S&SL)
END zjJyc?
EXEC (@TruncLog) `[1]wV5(5@
END 0$49X
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Y.Ew;\6U
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + Vk~}^;`Y
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' WqU$cQD"
FROM sysfiles WI'csM;M#
WHERE name = @LogicalFileName J.`.lQ$z
DROP TABLE DummyTrans B "}GAk}V
SET NOCOUNT OFF 7,LT4wYH
8、说明:更改某个表 PwNLJj+%
exec sp_changeobjectowner 'tablename','dbo' )'<zC
9、存储更改全部表 2W~2Hk=0+%
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch /ci.IT$Q^
@OldOwner as NVARCHAR(128), +Q_Gm3^
@NewOwner as NVARCHAR(128) ,|c_l)
AS $S cjEG:6
DECLARE @Name as NVARCHAR(128) wy&*6>.
DECLARE @Owner as NVARCHAR(128) KoXXNJax
DECLARE @OwnerName as NVARCHAR(128) %r,2ZLZ
DECLARE curObject CURSOR FOR bFx?HM.AGW
select 'Name' = name, W]*wxzf!5z
'Owner' = user_name(uid) $1@{Zz!S
from sysobjects p9sxA|O=y
where user_name(uid)=@OldOwner mg;AcAS.o,
order by name {DO9{96w4
OPEN curObject bo"I:)n;
FETCH NEXT FROM curObject INTO @Name, @Owner <(t<gS #
WHILE(@@FETCH_STATUS=0) %E!0,y,:
BEGIN ^
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if @Owner=@OldOwner mLYB6
begin 1Q$ M/}
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 3a S>U #
exec sp_changeobjectowner @OwnerName, @NewOwner 4'8.f5
end ";. 3+z
-- select @name,@NewOwner,@OldOwner nBj7 Q!lW
FETCH NEXT FROM curObject INTO @Name, @Owner |3cR'|<Ual
END liB>~DVC
close curObject y@z#Jw<
deallocate curObject t2$:*PvE
GO Q&\k"X 1
10、SQL SERVER中直接循环写入数据 Te/)[I'Tn
declare @i int 1|89-Ii]
set @i=1 d$Xvax,C
while @i<30 cS[`1y,\3
begin vT~ a}
insert into test (userid) values(@i) 5VcYdu3
set @i=@i+1 2g v(`NKYE
end M;bQid@BG
小记存储过程中经常用到的本周,本月,本年函数 +Snjb0
Dateadd(wk,datediff(wk,0,getdate()),-1) 5f5`7uVJF
Dateadd(wk,datediff(wk,0,getdate()),6) 0.5_,an3
Dateadd(mm,datediff(mm,0,getdate()),0) /L
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Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ,O+7nByi[V
Dateadd(yy,datediff(yy,0,getdate()),0) h^)2:0#{I
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) hU{%x#8}lK
上面的SQL代码只是一个时间段 Ui.F<,E
Dateadd(wk,datediff(wk,0,getdate()),-1) V+q RDQ
Dateadd(wk,datediff(wk,0,getdate()),6) -wt2ydzos
就是表示本周时间段. '$VR_N\
下面的SQL的条件部分,就是查询时间段在本周范围内的: }R x%&29&
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) zkOgL9
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而在存储过程中 |+bG~~~%j
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) H6eGLg={
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) F*=RP$sj