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。 otfmM]f
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一、基础 xQU//kNL
1、说明:创建数据库 H }]Zp
CREATE DATABASE database-name Ly3!0P.<
2、说明:删除数据库 d}tmZ*q
drop database dbname 4n@>gW
3、说明:备份sql server uD?RL~M
--- 创建 备份数据的 device )P? F ni}
USE master QV.>Cy
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' $y,KDR7^
--- 开始 备份 <bo^u w
BACKUP DATABASE pubs TO testBack n#Dy
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4、说明:创建新表 4M> pHz4
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) X lItg\R
根据已有的表创建新表: 1LSJy*yY
A:create table tab_new like tab_old (使用旧表创建新表) xb%Q[V_m
B:create table tab_new as select col1,col2... from tab_old definition only 7w" !"W#
5、说明:删除新表 B~k{f}
drop table tabname '3U,UD5EG
6、说明:增加一个列 )B+o
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Alter table tabname add column col type $GU s\
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 ("PZ!z1m1
7、说明:添加主键: Alter table tabname add primary key(col) 9M'"q7Kh
说明:删除主键: Alter table tabname drop primary key(col) R-dv$z0
8、说明:创建索引:create [unique] index idxname on tabname(col....) G7|d$!%
删除索引:drop index idxname rqiH!R
注:索引是不可更改的,想更改必须删除重新建。 rp
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9、说明:创建视图:create view viewname as select statement !vRN'/(Vyu
删除视图:drop view viewname gY[G>D=
10、说明:几个简单的基本的sql语句 TTl9xs,nO
选择:select * from table1 where 范围 DJ7ak>"R
插入:insert into table1(field1,field2) values(value1,value2) jtpHDS
删除:delete from table1 where 范围 d}fd^x/
更新:update table1 set field1=value1 where 范围 Sz<:WY/(x
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Gey-8
排序:select * from table1 order by field1,field2 [desc] p/Q< VV
总数:select count as totalcount from table1 V"(5U(v{~
求和:select sum(field1) as sumvalue from table1 ,r~^<m
平均:select avg(field1) as avgvalue from table1 l3BN,HNv+
最大:select max(field1) as maxvalue from table1 l3u+fE,;_
最小:select min(field1) as minvalue from table1 s.rQiD
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11、说明:几个高级查询运算词 R[6R)#o
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A: UNION 运算符 o6|-
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UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 lH`c&LL-=!
B: EXCEPT 运算符 "Dk@-Ac
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 *0@Z+'M?
C: INTERSECT 运算符 jg'"?KSU~
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 D4(73
注:使用运算词的几个查询结果行必须是一致的。 frm[<-~ w0
12、说明:使用外连接 Yc-5Mr8*,
A、left outer join: 8YE4ln
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 YU0pWM
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ^`dMjeF
B:right outer join: *oIIcE4g7
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 W^Fkjqpv
C:full outer join: t4d/%b~{:U
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 YGM7? o
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二、提升 5uSg]2:
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) Gs|a$^V|o
法一:select * into b from a where 1<>1 g'T L`=O
法二:select top 0 * into b from a B/K=\qmm
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) @oj_E0i3
insert into b(a, b, c) select d,e,f from b; kSol%C
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) *P7n YjG
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 <3tf(?*,k]
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. P8=J0&5
4、说明:子查询(表名1:a 表名2:b) y]obO|AH
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) ?P9VdS1-
5、说明:显示文章、提交人和最后回复时间 `FNU-
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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 k5tyOk
6、说明:外连接查询(表名1:a 表名2:b) oNl-!W
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 ]ZUK
7、说明:在线视图查询(表名1:a ) ^-s7>F`jx
select * from (SELECT a,b,c FROM a) T where t.a > 1; f>mEX='w
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 oa7 N6
select * from table1 where time between time1 and time2 5syzh
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select a,b,c, from table1 where a not between 数值1 and 数值2 ASMItT
9、说明:in 的使用方法 -:L7iOzgD
select * from table1 where a [not] in ('值1','值2','值4','值6') PIFZ '6gn
10、说明:两张关联表,删除主表中已经在副表中没有的信息 R6>*n!*D@
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ^mI`P}5Y
11、说明:四表联查问题: v6aMYmenBH
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 ..... SI%J+Y7
12、说明:日程安排提前五分钟提醒 SJj_e-
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 #=Xa(<t
13、说明:一条sql 语句搞定数据库分页 ujX\^c
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 2++$ Ql/
14、说明:前10条记录 >dF #1
select top 10 * form table1 where 范围 { i3x\|
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.) <b\.d^=B
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) hZUS#75M5
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 jL4"FTcE]3
(select a from tableA ) except (select a from tableB) except (select a from tableC) RN1KM
17、说明:随机取出10条数据 #q0xlF@
select top 10 * from tablename order by newid() #\Q)7pgi.
18、说明:随机选择记录 W0U|XX!&
select newid() p((. (fx
19、说明:删除重复记录 P??pWzb6HH
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) JPT&!%~
20、说明:列出数据库里所有的表名 U'5p;j)_
select name from sysobjects where type='U' lu.xv6+
21、说明:列出表里的所有的 F3Vvqt*2
select name from syscolumns where id=object_id('TableName') U;.cXU{
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|>IV
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 2%fkXH<
显示结果: [vY)y\W{
type vender pcs p"cY/2w:j
电脑 A 1 l`0JL7
电脑 A 1 ao2o!-?!t
光盘 B 2 5y0LkuRR:
光盘 A 2 T_)+l)
手机 B 3 EmP2r*"rb
手机 C 3 P:XX8
23、说明:初始化表table1 [ CU8%%7
TRUNCATE TABLE table1 55>+%@$,a
24、说明:选择从10到15的记录 c No)LF
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Pff-eT+~m
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三、技巧 aM8z_j!!u
1、1=1,1=2的使用,在SQL语句组合时用的较多 /~<Przw
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 5KYR"-jY
如: u<j.XPK
if @strWhere !='' }zeKf/?'
begin Xa>c]j
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere RhjU^,%
end X)9|ZF2`
else 7#T@CKdUd
begin &.0 wPyw
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' Dp@m"_1`+
end a5@lWpQsV
我们可以直接写成 >6;RTN/P2
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere cetlr
2、收缩数据库 }LZz"b<aw
--重建索引 ,Qe`(vU*s
DBCC REINDEX :KRe==/
DBCC INDEXDEFRAG aO\@5i_r
--收缩数据和日志 dUceZmAl
DBCC SHRINKDB Gh'{O/F4*
DBCC SHRINKFILE :J5CmU$
3、压缩数据库 uk.x1*0x
dbcc shrinkdatabase(dbname) *;.:UR[i
4、转移数据库给新用户以已存在用户权限 `5~<)
exec sp_change_users_login 'update_one','newname','oldname' U.WMu%
go k}{K7,DM
5、检查备份集 DB] ]6
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' d
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6、修复数据库 [vCZD8"Y8
ALTER DATABASE [dvbbs] SET SINGLE_USER _j_c&
GO :Sk<0VVd7
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 1;MUemnx`
GO qRZLv7X*j
ALTER DATABASE [dvbbs] SET MULTI_USER y=}a55:qE
GO mO\=#Q>
7、日志清除 jin?;v
SET NOCOUNT ON r3Ih]|FK#
DECLARE @LogicalFileName sysname, D4GXZX8K
@MaxMinutes INT, D2#.qoP #
@NewSize INT =1F F2#zS
USE tablename -- 要操作的数据库名 ."v&?o
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ou&7v<)x4
@MaxMinutes = 10, -- Limit on time allowed to wrap log. pQ+4++7ID
@NewSize = 1 -- 你想设定的日志文件的大小(M) YH!` uU(Lh
-- Setup / initialize ~x+24/qT
DECLARE @OriginalSize int _P]k6z+
SELECT @OriginalSize = size >Gxu8,_;
FROM sysfiles @/?$ ZX/e[
WHERE name = @LogicalFileName oX1{~lDJl
SELECT 'Original Size of ' + db_name() + ' LOG is ' + opxPK=kJ
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ds
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' fbW#6:Y
FROM sysfiles Wuji'sxTs
WHERE name = @LogicalFileName W&a<Q)o*I
CREATE TABLE DummyTrans {D&:^f
(DummyColumn char (8000) not null) \hZ9in`YlR
DECLARE @Counter INT, <.6$zcW
@StartTime DATETIME, 9hs7B!3pc>
@TruncLog VARCHAR(255) 3^AS8%qG
SELECT @StartTime = GETDATE(), z#|tl/aP9
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' `\S~;O
DBCC SHRINKFILE (@LogicalFileName, @NewSize) .J|"bs9
EXEC (@TruncLog) ^`!EpO>k9
-- Wrap the log if necessary. o"A%dC_
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired YPav5<{a
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) P}Ul e|&LK
AND (@OriginalSize * 8 /1024) > @NewSize =
P{]3K
BEGIN -- Outer loop. R:DW>LB
SELECT @Counter = 0 j6)@kW9x
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) })r[qsv
BEGIN -- update ='r4zz
INSERT DummyTrans VALUES ('Fill Log') E)l@uPA'1
DELETE DummyTrans nbz?D_
SELECT @Counter = @Counter + 1 Rs%6O|u7
END {mV,bg,}~
EXEC (@TruncLog) c7N`W}BZ
END -n$fh::^
SELECT 'Final Size of ' + db_name() + ' LOG is ' + r`/tb^
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + w-MnJ(r
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' %!1:BQ,p,i
FROM sysfiles +EgQj*F*
WHERE name = @LogicalFileName I"+;L4o `
DROP TABLE DummyTrans <%rG*vzi
SET NOCOUNT OFF yq>3IS4O
8、说明:更改某个表 MA:8gD
exec sp_changeobjectowner 'tablename','dbo' Z$5@r2d)
9、存储更改全部表 m)?cXM
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch eJ!a8
@OldOwner as NVARCHAR(128), 3AD^B\<gB
@NewOwner as NVARCHAR(128) tpi63<N
AS "n@=.x
DECLARE @Name as NVARCHAR(128) jW+L0RkX
DECLARE @Owner as NVARCHAR(128) mYzq[p_|j
DECLARE @OwnerName as NVARCHAR(128) j^~WAWbFh
DECLARE curObject CURSOR FOR %@jv\J
select 'Name' = name, Iih~rWJ
'Owner' = user_name(uid) yN~: 3
from sysobjects Lw.N3!e[
where user_name(uid)=@OldOwner vg1p{^N!
order by name E8Wgm
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OPEN curObject KArnNmJ9
FETCH NEXT FROM curObject INTO @Name, @Owner eESJk14
WHILE(@@FETCH_STATUS=0) }3!.e
BEGIN PV%7m7=x
if @Owner=@OldOwner hU `H\LE
begin cS ;hyLd
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 9Kyr/6w4-k
exec sp_changeobjectowner @OwnerName, @NewOwner =lG5Kc{B
end 8f |
-- select @name,@NewOwner,@OldOwner 8ESBui3;
FETCH NEXT FROM curObject INTO @Name, @Owner pOip$Z
END [0}^w[
close curObject A{hWFSv
deallocate curObject >c7fg^@
GO Piz/vH6M}
10、SQL SERVER中直接循环写入数据 d&0^AvM@
declare @i int Os1(28rl
set @i=1 .
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while @i<30 TlZ|E '_C
begin \^3\_T&6
insert into test (userid) values(@i) #f@sq5pTO
set @i=@i+1 z>hG'
end 4jrY3gyBX
小记存储过程中经常用到的本周,本月,本年函数 ,.fGZ4
Dateadd(wk,datediff(wk,0,getdate()),-1) cQUmcK/,
Dateadd(wk,datediff(wk,0,getdate()),6) u<\/T&S
Dateadd(mm,datediff(mm,0,getdate()),0) #x&1kHu<
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) e p;_'
Dateadd(yy,datediff(yy,0,getdate()),0) yHhBUpIo
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) -$4PY,
上面的SQL代码只是一个时间段 6kKIDEX
Dateadd(wk,datediff(wk,0,getdate()),-1) e2%Y8ZJG.
Dateadd(wk,datediff(wk,0,getdate()),6) 4>>d
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就是表示本周时间段.
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下面的SQL的条件部分,就是查询时间段在本周范围内的: ?+b )=Z
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) g(MeCoCc
而在存储过程中 =8fp4#]7
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) dM 7-,9Vc
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 5o2;26c