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。 jEI!t^#
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一、基础 ry
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1、说明:创建数据库 %?
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CREATE DATABASE database-name Nd6N:1-
2、说明:删除数据库 Dk7"#q@kx
drop database dbname E3KPjK
3、说明:备份sql server |0Zj/1<$
--- 创建 备份数据的 device _p~
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USE master z?i82B[Tm
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' L' )(Zn1
--- 开始 备份 2<J82(4j
BACKUP DATABASE pubs TO testBack &!_Ko`b8K
4、说明:创建新表 Ep'C FNbtW
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) "iKK&%W
根据已有的表创建新表: CP?\'a"Kt
A:create table tab_new like tab_old (使用旧表创建新表) m.4y=69 &
B:create table tab_new as select col1,col2... from tab_old definition only Q.8Jgel1
5、说明:删除新表 &MKv_
drop table tabname >%W"u`Q
6、说明:增加一个列 I/@Xr
Alter table tabname add column col type Rn TPU`
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。 O=+C Kx@
7、说明:添加主键: Alter table tabname add primary key(col) *]H ./a:1
说明:删除主键: Alter table tabname drop primary key(col) hz/5k%%UX
8、说明:创建索引:create [unique] index idxname on tabname(col....) qI'a|p4fn?
删除索引:drop index idxname '<@ PgO~
注:索引是不可更改的,想更改必须删除重新建。 Su-+~`
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9、说明:创建视图:create view viewname as select statement ,*bxNs'/
删除视图:drop view viewname }y0UyOa{C
10、说明:几个简单的基本的sql语句 g|T' oK
选择:select * from table1 where 范围 *k=}g][?
插入:insert into table1(field1,field2) values(value1,value2) 2xjS;lpw
删除:delete from table1 where 范围 k,&W5zBKe
更新:update table1 set field1=value1 where 范围 GN{.R7
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! `"D7XC0x
排序:select * from table1 order by field1,field2 [desc] S5uV\Y/A
总数:select count as totalcount from table1 B)c.`cfr*\
求和:select sum(field1) as sumvalue from table1 #6YNgJNk
平均:select avg(field1) as avgvalue from table1 a-kU?&*
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最大:select max(field1) as maxvalue from table1 !WIL|\jbh
最小:select min(field1) as minvalue from table1 lvFHr}W
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11、说明:几个高级查询运算词 *F9uv)[kz
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A: UNION 运算符 )@sz\yI%U
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。 +V0uHpm
B: EXCEPT 运算符 `rM-b'D
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。 EGa}ml/G
C: INTERSECT 运算符 SWmdU]
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。 czT$mKj3
注:使用运算词的几个查询结果行必须是一致的。 Aimgfxag
12、说明:使用外连接 ukPV nk
A、left outer join: E]e6a^J#
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 bZKK'd$I
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 8d>OtDLa
B:right outer join: 3|~(9b{+
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。 !u=[/>
C:full outer join: uH7u4f1Q
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。 yqAw7GaBN
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二、提升 Ig=4Z*au!g
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) L>PpXTWwy
法一:select * into b from a where 1<>1 gfp#G,/B
法二:select top 0 * into b from a p2cKtk+
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) i,V~5dE[I<
insert into b(a, b, c) select d,e,f from b; :0vNg:u+
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) . Bv;Zv
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 jgC/
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 3c
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4、说明:子查询(表名1:a 表名2:b) bS0LjvY9g
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) Nlo*vu
5、说明:显示文章、提交人和最后回复时间 UZdpKi@
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 38f9jF%7j
6、说明:外连接查询(表名1:a 表名2:b) _@HMk"A
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c _E?(cWC
7、说明:在线视图查询(表名1:a ) W;o\}irep
select * from (SELECT a,b,c FROM a) T where t.a > 1; gjwp' GN
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 .m4K ]^m
select * from table1 where time between time1 and time2 dvUJk<;w
select a,b,c, from table1 where a not between 数值1 and 数值2 jd$lu^>I
9、说明:in 的使用方法 x0 j$]$
select * from table1 where a [not] in ('值1','值2','值4','值6') {Ynr(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 p;C`n)7P7
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 0z%]HlPg
11、说明:四表联查问题: 6>KDK<5NQ
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 ..... 3ldOOQW%
12、说明:日程安排提前五分钟提醒 -\r*D#aHBN
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 VpD9!;S
13、说明:一条sql 语句搞定数据库分页 "Z,'NL>&
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 iJ#sg+
14、说明:前10条记录 44cyD _(
select top 10 * form table1 where 范围 z*kn.sW
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.) 92S<TAdPP
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 5Rc
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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 *}LYMrP
(select a from tableA ) except (select a from tableB) except (select a from tableC) 2!l)%F`
17、说明:随机取出10条数据 ;Qw>&24h[
select top 10 * from tablename order by newid() F_@PSA+
18、说明:随机选择记录 E5Z,4B
select newid() IV!&jL
19、说明:删除重复记录 Pxl7zz&pl=
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) &a7KdGP8V
20、说明:列出数据库里所有的表名 0Y[mh@(
select name from sysobjects where type='U' l0]z Zcpt
21、说明:列出表里的所有的 #N7@p}P
select name from syscolumns where id=object_id('TableName') "tm2YUG},s
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。 W4X=.vr
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 K /. ;N.9
显示结果: >/-<,,<\C
type vender pcs @m#7E4+
电脑 A 1 02b v0
电脑 A 1 o-49o5:1
光盘 B 2 ?7(`2=J
光盘 A 2 St'3e<
手机 B 3 |wWBV{^
手机 C 3 `a
23、说明:初始化表table1 zQ5'q
TRUNCATE TABLE table1 U
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24、说明:选择从10到15的记录 \z0"
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ~-|K5
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三、技巧 D/Bb)]9I
1、1=1,1=2的使用,在SQL语句组合时用的较多 #6@7XC
"where 1=1" 是表示选择全部 "where 1=2"全部不选, >e'6RZRLA
如: @G^
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if @strWhere !='' Nx,.4CI
begin O57
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere He~)i)co
end 3/oVl
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else ^jq QG+`?
begin jDOB(fE
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' %Q]m6ciAM
end 3)p#}_u{
我们可以直接写成 RCgZ GP
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere {rf.sN~M
2、收缩数据库 vm
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--重建索引 "0pu_
DBCC REINDEX IL*C/y
DBCC INDEXDEFRAG SfEgmp-m
--收缩数据和日志 %h(J+_"L6
DBCC SHRINKDB #]cO]
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DBCC SHRINKFILE M qFuZg
3、压缩数据库 w+z~Mz}Vz
dbcc shrinkdatabase(dbname) Xu2:yf4No*
4、转移数据库给新用户以已存在用户权限 "NMX>a,(
exec sp_change_users_login 'update_one','newname','oldname' `[X5mEe
go jgK8} C
5、检查备份集 +?DP r
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' MZl6J
6、修复数据库 ^yyL4{/
ALTER DATABASE [dvbbs] SET SINGLE_USER !^:b?M
GO 'QeCJ5p]
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ,l1A]Wx
GO ot8UuBq
ALTER DATABASE [dvbbs] SET MULTI_USER !.Eua3:V*
GO 4'Potv@/
7、日志清除 |@!4BA
SET NOCOUNT ON !EB<e5}8wK
DECLARE @LogicalFileName sysname, F4 `ud;1H
@MaxMinutes INT, 4|ML#aRz
@NewSize INT _H}8eU
USE tablename -- 要操作的数据库名 PuYAoKG
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 $~W=)f9
@MaxMinutes = 10, -- Limit on time allowed to wrap log. WzDL(~m+Z
@NewSize = 1 -- 你想设定的日志文件的大小(M) =c8xg/
-- Setup / initialize }(FF^Mh
DECLARE @OriginalSize int S ( e]@
SELECT @OriginalSize = size DI"KH)XD
FROM sysfiles ckykRqk}
WHERE name = @LogicalFileName $3psSQQo
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 14Y_ oH9
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + {(Jbgsxm
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' r01Z
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FROM sysfiles !Z]#1"A8
WHERE name = @LogicalFileName KxhMPvN'
CREATE TABLE DummyTrans n
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(DummyColumn char (8000) not null) Gl;xd
DECLARE @Counter INT, @{n"/6t
@StartTime DATETIME, 3)cH\gsg9
@TruncLog VARCHAR(255) AAuH}W>n
SELECT @StartTime = GETDATE(), >BFUts%
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' }$
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) wIeF(}VM
EXEC (@TruncLog) /u?ZwoTzY
-- Wrap the log if necessary. v,,
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ||yx?q6\h
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 57@6O-t-
AND (@OriginalSize * 8 /1024) > @NewSize %wil'
BEGIN -- Outer loop. .6C9N{?Tqf
SELECT @Counter = 0 %'+}-w
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) pUF$Nq>og
BEGIN -- update /;E{(%U)t
INSERT DummyTrans VALUES ('Fill Log') r`-=<@[
DELETE DummyTrans 5!-+5TJI
SELECT @Counter = @Counter + 1 ZP-^10
END >L4q>S^v
EXEC (@TruncLog) n4Xh}KtH
END $y{rM%6JU
SELECT 'Final Size of ' + db_name() + ' LOG is ' + =^ZDP1h/}
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + IE]? WW5
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' <<WqL?8W
FROM sysfiles ^-nL!>FYY
WHERE name = @LogicalFileName c`,'[Q5(O
DROP TABLE DummyTrans 7C / ^Gw
SET NOCOUNT OFF yrvV<}
8、说明:更改某个表 AcHr X=O
exec sp_changeobjectowner 'tablename','dbo' aoqG*qh}b
9、存储更改全部表 =Vie0TV&h
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch \0j-p
@OldOwner as NVARCHAR(128), 2Sgv
@NewOwner as NVARCHAR(128) Oz{FM6
AS Z; 6N7U
DECLARE @Name as NVARCHAR(128) d%,@,>>)
DECLARE @Owner as NVARCHAR(128) "~2SHM@q
DECLARE @OwnerName as NVARCHAR(128) ?COLjk
DECLARE curObject CURSOR FOR zy'e|92aO
select 'Name' = name, E5iNuJj=f
'Owner' = user_name(uid) 1L;3e@G
from sysobjects MxLg8,M
where user_name(uid)=@OldOwner
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order by name v]h^0WU
OPEN curObject +khVi}
FETCH NEXT FROM curObject INTO @Name, @Owner .D3k(zZ
WHILE(@@FETCH_STATUS=0) '><I|c}
BEGIN DMdVE P"m
if @Owner=@OldOwner h~`^H9?M
begin kY?w] lS)t
set @OwnerName = @OldOwner + '.' + rtrim(@Name) W*;r}!ro
exec sp_changeobjectowner @OwnerName, @NewOwner 4++
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end tNvjwgV\
-- select @name,@NewOwner,@OldOwner dkWV/DAm
FETCH NEXT FROM curObject INTO @Name, @Owner |1%eo.
END &v)/mc7D
close curObject do[w&`jw8
deallocate curObject x1`4hB
GO `eEiSf
10、SQL SERVER中直接循环写入数据 w!_6*
declare @i int ;UpdkY
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set @i=1 u u$Jwn!S
while @i<30 Yr)<1.K4,M
begin <sTY<i VR
insert into test (userid) values(@i) 7S/\;DF
set @i=@i+1 yz7Fe
end 7u`:e,'
小记存储过程中经常用到的本周,本月,本年函数 Og-v][
Dateadd(wk,datediff(wk,0,getdate()),-1) W"!{f
Dateadd(wk,datediff(wk,0,getdate()),6) hsAk7KC
Dateadd(mm,datediff(mm,0,getdate()),0) sa?s[
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) .^xQtnq
Dateadd(yy,datediff(yy,0,getdate()),0) U!
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) qDS~|<Y5
上面的SQL代码只是一个时间段 <5!)5+G
Dateadd(wk,datediff(wk,0,getdate()),-1) \_)[FC@
Dateadd(wk,datediff(wk,0,getdate()),6) M{t/B-'4
就是表示本周时间段. :z-?L0C=0
下面的SQL的条件部分,就是查询时间段在本周范围内的: fl8eNiE|
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) uCx6/n6'
而在存储过程中 ujW C!*W(Q
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) oD3]2o /
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 9\Md.>