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。 &\m=|S
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一、基础 xtFGj,N
1、说明:创建数据库 5MHcgzyp
CREATE DATABASE database-name #D ]P3
2、说明:删除数据库 G/N 1[)
drop database dbname E2i'lO\P
3、说明:备份sql server ]S+KH
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--- 创建 备份数据的 device Y_=
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USE master *b,4qMr
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' k{C03=xk
--- 开始 备份 zFm:=,9
BACKUP DATABASE pubs TO testBack Y{I,ipU.
4、说明:创建新表 1)t*l;.
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) B*OBXN>'P
根据已有的表创建新表: C0gO^A.d
A:create table tab_new like tab_old (使用旧表创建新表) "L&84^lmf
B:create table tab_new as select col1,col2... from tab_old definition only XP^[,)E
5、说明:删除新表 ,!vI@>nhG
drop table tabname :y1,OR/k
6、说明:增加一个列 #5yz~&
Alter table tabname add column col type Qpocj:
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。 $nqVE{ksV
7、说明:添加主键: Alter table tabname add primary key(col) YLv5[pV
说明:删除主键: Alter table tabname drop primary key(col) ^^T
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8、说明:创建索引:create [unique] index idxname on tabname(col....) fJD+GvV$x
删除索引:drop index idxname ?)O!(=6%'
注:索引是不可更改的,想更改必须删除重新建。 PrhGp
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9、说明:创建视图:create view viewname as select statement _^@ >I8ix
删除视图:drop view viewname b_w(F_0
10、说明:几个简单的基本的sql语句 LhCwZ1
选择:select * from table1 where 范围 !X4m6gRaP
插入:insert into table1(field1,field2) values(value1,value2) CLgfNrW~
删除:delete from table1 where 范围 SsCV}[
更新:update table1 set field1=value1 where 范围 ?+G
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查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! @iBaJ"*,
排序:select * from table1 order by field1,field2 [desc] c>%%'c
总数:select count as totalcount from table1 ^i!I0Q2yd
求和:select sum(field1) as sumvalue from table1 vw6DHN)k
平均:select avg(field1) as avgvalue from table1 !,9;AMO
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最大:select max(field1) as maxvalue from table1 ")Qhg-l
最小:select min(field1) as minvalue from table1 ST1c`0e
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11、说明:几个高级查询运算词 dLbSvK<(I
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A: UNION 运算符 F% z$^ m-
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 _c>8y
B: EXCEPT 运算符 4SJb\R)XK
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 I~Q
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C: INTERSECT 运算符
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INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。
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注:使用运算词的几个查询结果行必须是一致的。 nLY(%):(P
12、说明:使用外连接 zALtG<_t
A、left outer join: o[%\W
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 ."Q}2
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 6,~]2H'zq
B:right outer join: lf\x`3Vd
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 LnPG+<
C:full outer join: p :zRgwcn
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 #|/+znJm
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二、提升 H,EGB8E2
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) PZihC
法一:select * into b from a where 1<>1 F^CR$L& K
法二:select top 0 * into b from a 1ZY~qP+n+
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用)
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insert into b(a, b, c) select d,e,f from b; .u:aX$t+
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) :6J&%n
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 y\_k8RqE^
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. #ri;{d^6
4、说明:子查询(表名1:a 表名2:b) 3z% W5[E)
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) U+,RP$r@
5、说明:显示文章、提交人和最后回复时间 ,olP}
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b yof8L WXx
6、说明:外连接查询(表名1:a 表名2:b) Nxr\Yey
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c NqM=Nu\
7、说明:在线视图查询(表名1:a ) "V`5 $ur
select * from (SELECT a,b,c FROM a) T where t.a > 1; rV}&G!V_t
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 v8K`cijSS
select * from table1 where time between time1 and time2 ]]P@*4!
select a,b,c, from table1 where a not between 数值1 and 数值2 4"veq rC
9、说明:in 的使用方法 ` <u2 N
select * from table1 where a [not] in ('值1','值2','值4','值6') ?\$6"c<G
10、说明:两张关联表,删除主表中已经在副表中没有的信息 6w~Cyu4Ov
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) +
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11、说明:四表联查问题: 06e dVIRr
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 ..... [1e]_9)p
12、说明:日程安排提前五分钟提醒 ~l}\K10L*
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 !8&EkXTw,
13、说明:一条sql 语句搞定数据库分页 [lGxys)J
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 gxmY^"Jy
14、说明:前10条记录 Xi;<O&+
select top 10 * form table1 where 范围 aSMoee@!
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.) hQeG#KQ
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Ax*xa6_2
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 mrBK{@n
(select a from tableA ) except (select a from tableB) except (select a from tableC) <R?S
17、说明:随机取出10条数据 j/;wxKW
select top 10 * from tablename order by newid() ]f>0P3O5&
18、说明:随机选择记录 pKU(4&BxX
select newid() :LCyxLI
19、说明:删除重复记录 0i>p1/kv
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ~ ReX$9
20、说明:列出数据库里所有的表名 >[l2KD
select name from sysobjects where type='U' Y
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21、说明:列出表里的所有的 J-qUJX~4c
select name from syscolumns where id=object_id('TableName') tIS.,CEQF
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 [I}z\3Z
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select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type ueEf>0
显示结果: 1024L;
type vender pcs e*Y<m\*
电脑 A 1 &+3RsIlW
电脑 A 1 /=g/{&3[a>
光盘 B 2 Yl=-j
光盘 A 2 Z!3R
手机 B 3 8nwps(3
手机 C 3 <[K3Prf C
23、说明:初始化表table1 @`ii3&W4
TRUNCATE TABLE table1 Dus!Ki~8(t
24、说明:选择从10到15的记录 5?[hr5E.E
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc jVh:Bw
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三、技巧 xQl}~G]!
1、1=1,1=2的使用,在SQL语句组合时用的较多 X#HH7V>
"where 1=1" 是表示选择全部 "where 1=2"全部不选, x~=Mn%Ew0
如: %cBOi_}}~
if @strWhere !='' 8Ltl32JSB[
begin Yr>0Qg],
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere [SD
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end hM[3l1o{|
else q]Kv.x]$R
begin bGkLa/?S
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' w|Ry)[
end f8ZuG !U
我们可以直接写成 5~ZzQG
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere qOIVuzi*
2、收缩数据库 =zu;npM
--重建索引 `"hWbmQ
DBCC REINDEX Kv)}
DBCC INDEXDEFRAG Fv$A%6;W
--收缩数据和日志 '$rCV,3q
DBCC SHRINKDB {+GR/l\!#
DBCC SHRINKFILE +o):grWvQ
3、压缩数据库 QN|=/c<U
dbcc shrinkdatabase(dbname) mX!*|$bs
4、转移数据库给新用户以已存在用户权限 ||ugb6q[6B
exec sp_change_users_login 'update_one','newname','oldname' eiXl"R^
go ZH*h1?\X
5、检查备份集 zl|
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' x6*y$D^B
6、修复数据库 wqT9m*VK
ALTER DATABASE [dvbbs] SET SINGLE_USER |3 Iug
GO 78r0K 5=
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Xvoz4'Gme
GO V.6pfL
ALTER DATABASE [dvbbs] SET MULTI_USER kKjcW` [
GO iSUu3Yv,_m
7、日志清除 |5ge4,}0
SET NOCOUNT ON /Kq'3[d8
DECLARE @LogicalFileName sysname, BO7XN;
@MaxMinutes INT, JVxja<43
@NewSize INT 0Lb{HLT
USE tablename -- 要操作的数据库名 luyu7`
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ,p /{!BX
@MaxMinutes = 10, -- Limit on time allowed to wrap log. k"C'8<T)'
@NewSize = 1 -- 你想设定的日志文件的大小(M) z'Z[mrLq
-- Setup / initialize :KR
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DECLARE @OriginalSize int ?#fm-5WIi
SELECT @OriginalSize = size !|j|rYi-
FROM sysfiles E m^Dg9
WHERE name = @LogicalFileName \ q3ui}-9
SELECT 'Original Size of ' + db_name() + ' LOG is ' + *A4eYHn@
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + [S8*b^t4
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' "RM\<)IF
FROM sysfiles 7=5eLc^
WHERE name = @LogicalFileName T\(k=0RM
CREATE TABLE DummyTrans @rAV;D%
(DummyColumn char (8000) not null) W/b)OlG"2
DECLARE @Counter INT, rV4K@)~
@StartTime DATETIME, sH_,P
@TruncLog VARCHAR(255) KU*aJl_n,
SELECT @StartTime = GETDATE(), 4=EA3`l
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 7S^G]g!x
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 8qaU[u&$
EXEC (@TruncLog) SH#*Lc
-- Wrap the log if necessary. -(>Ch>O
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired FvYciU!
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) as('ZD.9
AND (@OriginalSize * 8 /1024) > @NewSize L &hw-.Q
BEGIN -- Outer loop. >fth
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SELECT @Counter = 0 )B)f`(SA"<
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) t1"#L_<e
BEGIN -- update hvQXYo>TZx
INSERT DummyTrans VALUES ('Fill Log') M_-L#FHX
DELETE DummyTrans i pl,{
SELECT @Counter = @Counter + 1 &:IcwD&
END E/*&'Osq
EXEC (@TruncLog) ;ISe@yR;
END k<CbI
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SELECT 'Final Size of ' + db_name() + ' LOG is ' + hqlQ-aytS
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + A0U9,M
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 2ZEGE+0
FROM sysfiles U*E)y7MY
WHERE name = @LogicalFileName \G7F/$g
DROP TABLE DummyTrans awvP;F?q|
SET NOCOUNT OFF @6UZC-M0
8、说明:更改某个表 \v5;t9uBZ
exec sp_changeobjectowner 'tablename','dbo' c#"t.j<E}
9、存储更改全部表 E`V\/`5D
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ;,e16^\' &
@OldOwner as NVARCHAR(128), esQ$.L
@NewOwner as NVARCHAR(128) Kop(+]Q&n
AS h3&|yS|
DECLARE @Name as NVARCHAR(128) Crg'AB?
DECLARE @Owner as NVARCHAR(128) B2P@9u|9
DECLARE @OwnerName as NVARCHAR(128) CaO-aL
DECLARE curObject CURSOR FOR ZTz07Jt
select 'Name' = name, |FM*1Q[1
'Owner' = user_name(uid) m4m|?
from sysobjects 4OQ,|Wm4G
where user_name(uid)=@OldOwner %=Z/Frd
order by name j*Pq<[~
OPEN curObject _MLf58
FETCH NEXT FROM curObject INTO @Name, @Owner "om7 :d
WHILE(@@FETCH_STATUS=0) 3)6- S
BEGIN pMy:h
if @Owner=@OldOwner "y&`,s5}
begin .|5$yGEF_+
set @OwnerName = @OldOwner + '.' + rtrim(@Name) QkW'tU\^
exec sp_changeobjectowner @OwnerName, @NewOwner >:> W=
end FKz5,PeL
-- select @name,@NewOwner,@OldOwner .RJMtmp
FETCH NEXT FROM curObject INTO @Name, @Owner rF"p7
END +egwZ$5I
close curObject n*A1x8tn
deallocate curObject Rz|@BxB>n
GO gGUKB2)
10、SQL SERVER中直接循环写入数据 `>`b;A4
declare @i int |:JT+a1
set @i=1 Xa.8-a"hz
while @i<30 S\<i`q
begin ^.\O)K {h
insert into test (userid) values(@i) mfaU_Vo&
set @i=@i+1 \`xlD&F@U
end _8
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小记存储过程中经常用到的本周,本月,本年函数 LybaE~=
Dateadd(wk,datediff(wk,0,getdate()),-1) geqP. MR
Dateadd(wk,datediff(wk,0,getdate()),6) *|Er;Thw
Dateadd(mm,datediff(mm,0,getdate()),0) 3Cc#{X-+
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) D\9-/p
Dateadd(yy,datediff(yy,0,getdate()),0) K)~a H
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) {vCtp
上面的SQL代码只是一个时间段 htR.p7&Tn
Dateadd(wk,datediff(wk,0,getdate()),-1) :op_J!;
Dateadd(wk,datediff(wk,0,getdate()),6) ],S {?!'1
就是表示本周时间段. 9jqsEd-SW
下面的SQL的条件部分,就是查询时间段在本周范围内的: @v2ko5
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) A$5M.
而在存储过程中
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) @`:X,]{
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Q= xXj'W-