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。 ,)V*xpp
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一、基础 $Z10Zf=
1、说明:创建数据库 uW;Uq=UN
CREATE DATABASE database-name _wM[U`H}s
2、说明:删除数据库 aVuan&]*=
drop database dbname =YA%=
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3、说明:备份sql server 8!>uC&bE8
--- 创建 备份数据的 device 23+6u{
USE master D]y6*Ha
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' e^~t52]
--- 开始 备份 oD{V_/pdx
BACKUP DATABASE pubs TO testBack A#1aO
4、说明:创建新表 f]T1:N*t
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) g/+M&k$
根据已有的表创建新表: l@1f L%f
A:create table tab_new like tab_old (使用旧表创建新表) &:]_a?|*S
B:create table tab_new as select col1,col2... from tab_old definition only *sJx0<!M}
5、说明:删除新表 F&lc8
drop table tabname Sc Gmft3A
6、说明:增加一个列 9Lz)SYd
Alter table tabname add column col type qCgP8U/jv
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。 a}E8ADyC
7、说明:添加主键: Alter table tabname add primary key(col) j K[VEhs
说明:删除主键: Alter table tabname drop primary key(col) 1:YDN.*
8、说明:创建索引:create [unique] index idxname on tabname(col....) yF0,}
删除索引:drop index idxname >4M_jC.
注:索引是不可更改的,想更改必须删除重新建。 \<lV),
9、说明:创建视图:create view viewname as select statement l$m^{6IYc
删除视图:drop view viewname ^0{S!fs
10、说明:几个简单的基本的sql语句 *B:{g>0
选择:select * from table1 where 范围 m OmT]X
插入:insert into table1(field1,field2) values(value1,value2) (!X:[Ah*$
删除:delete from table1 where 范围 tY# F8a&
更新:update table1 set field1=value1 where 范围 ^D4 b\mF
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 73}k[e7e
排序:select * from table1 order by field1,field2 [desc] 3%EwA\V(
总数:select count as totalcount from table1 =j;o,
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求和:select sum(field1) as sumvalue from table1 sef!hS06
平均:select avg(field1) as avgvalue from table1 njUM>E,'
最大:select max(field1) as maxvalue from table1 fE7WLV2I>
最小:select min(field1) as minvalue from table1 8-?n<h%8E
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11、说明:几个高级查询运算词 KAsS= `
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A: UNION 运算符 *"zE,Bp"
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。
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B: EXCEPT 运算符 (/*-M]>
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。 J.?p?-"
C: INTERSECT 运算符 _cGiuxf
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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。 _l8oB)
注:使用运算词的几个查询结果行必须是一致的。 H~V=TEj
12、说明:使用外连接 !Aw.f!
A、left outer join: Ue,"CQ6H
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。 _R-#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 0e7v ?UT
B:right outer join: ;QEGr|(
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。 i-ogeR?
C:full outer join: uo%O\}#u9
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。 \pPq]k
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二、提升 =)I{KT:y
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) wK\SeX
法一:select * into b from a where 1<>1 q?0goL
法二:select top 0 * into b from a (Q&z1XK3
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) /:USpuu
insert into b(a, b, c) select d,e,f from b; 'Gt`3qG
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) =G72`]#-
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 X@D3
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. A6U6SvM;
4、说明:子查询(表名1:a 表名2:b) bg=`
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) ?b7vc^E&
5、说明:显示文章、提交人和最后回复时间 gTQ6B,`/8
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b Xs?>6i@$$
6、说明:外连接查询(表名1:a 表名2:b) rU~"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 [X=eCHB?
7、说明:在线视图查询(表名1:a ) ^al
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select * from (SELECT a,b,c FROM a) T where t.a > 1; >C&!#
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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 ^a}{u$<
select * from table1 where time between time1 and time2 v0xi(Wu
select a,b,c, from table1 where a not between 数值1 and 数值2 6R,;c7Izhd
9、说明:in 的使用方法 d
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select * from table1 where a [not] in ('值1','值2','值4','值6') 4OIN@n*4
10、说明:两张关联表,删除主表中已经在副表中没有的信息 8'quQCx*=
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 7SM/bJ-M#
11、说明:四表联查问题: 6/n;u{|
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... mcR!P~"i
12、说明:日程安排提前五分钟提醒 EnUo B<
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 V('b|gsEo
13、说明:一条sql 语句搞定数据库分页 a*D|$<V
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 D2mB4
14、说明:前10条记录 zld>o3K}
select top 10 * form table1 where 范围 xAO]u[J
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.) tvH)I px
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) DxD0iJ=W
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 V , "'k<y
(select a from tableA ) except (select a from tableB) except (select a from tableC) @kK=|(OB'
17、说明:随机取出10条数据 xSUR<
select top 10 * from tablename order by newid() -|T^
18、说明:随机选择记录 >@|<1Fx|
select newid() d^Wh-U
19、说明:删除重复记录 lt]U?VZ
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) . =5Jpo
20、说明:列出数据库里所有的表名 iUKj:q:
select name from sysobjects where type='U' (M=Br
21、说明:列出表里的所有的 4CCux4)N
select name from syscolumns where id=object_id('TableName') 0k>&MkM\^
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。 6]3ZUH;
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 -,tYfQ;:
显示结果: ]aR4U`
type vender pcs /l`XJs
电脑 A 1 j
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电脑 A 1 ,jWd?-NH
光盘 B 2 X>4`{x `
光盘 A 2 -jy"?]ve.
手机 B 3 Rju8%FRO
手机 C 3 vP2QAGk<
23、说明:初始化表table1 +u2Co_FJ&
TRUNCATE TABLE table1 4s8E:I=K
24、说明:选择从10到15的记录 mc=*wr$
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc :6 fQE#(s&
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三、技巧 ZL>V9UWN
1、1=1,1=2的使用,在SQL语句组合时用的较多 P(;c`
"where 1=1" 是表示选择全部 "where 1=2"全部不选, #Q"vwek
如: #jJcgR<
if @strWhere !='' YMd&+J`
begin $^!w`>0C
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere F~AS(sk
end f0s
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else Zy%Z]dF
begin &^H
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' U!5*V9T~J
end (n/1:'
我们可以直接写成 )8SP$
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere {+:XVT_+
2、收缩数据库 =1VH5pVr}
--重建索引 m { fQL
DBCC REINDEX Uz|]}t5V
DBCC INDEXDEFRAG (0Cszm.
--收缩数据和日志 [//f BO
DBCC SHRINKDB >B
DBCC SHRINKFILE d@tr]v5 B
3、压缩数据库 `[CJtd2\
dbcc shrinkdatabase(dbname) p#d UL9
4、转移数据库给新用户以已存在用户权限 Wwha?W>
exec sp_change_users_login 'update_one','newname','oldname' -#6*T,f0P(
go ;%<4U^2
5、检查备份集 Y ,yaB)&Ih
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' @45 H8|:k
6、修复数据库 5XI*I(.%/
ALTER DATABASE [dvbbs] SET SINGLE_USER A.O~'')X
GO H\mVK!](D
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK #pSOZX
GO 836m5/kH[
ALTER DATABASE [dvbbs] SET MULTI_USER 1,QZnF!.x
GO [r8 d+
7、日志清除 a7\L-T+
SET NOCOUNT ON yXx62J
DECLARE @LogicalFileName sysname, |vz;bJG
@MaxMinutes INT, ssITe.,ny
@NewSize INT QJWES%m`
USE tablename -- 要操作的数据库名 o(/ia3
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 %n25Uq
@MaxMinutes = 10, -- Limit on time allowed to wrap log. L0b]^_tI
@NewSize = 1 -- 你想设定的日志文件的大小(M) +c`C9RXk
-- Setup / initialize !h>$bm
DECLARE @OriginalSize int ukf\*
SELECT @OriginalSize = size 2bnIT>(
FROM sysfiles JK"uj%
WHERE name = @LogicalFileName .oj" ru
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 43=-pyp
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ?]D+H%3[$i
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' y%bqeo
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FROM sysfiles Os 2YZ<t
WHERE name = @LogicalFileName }#*zjMOz
CREATE TABLE DummyTrans h<ct W>6v
(DummyColumn char (8000) not null) l0\>zWLZZ9
DECLARE @Counter INT, /%9p9$kFot
@StartTime DATETIME, AdOAh y2H
@TruncLog VARCHAR(255) *9Js:z7I
SELECT @StartTime = GETDATE(), ( L\G!pP.
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' */dh_P<Yj
DBCC SHRINKFILE (@LogicalFileName, @NewSize) X]MM7hMuR
EXEC (@TruncLog) -!G#")<
-- Wrap the log if necessary. u6I0<i_KZ
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 8sF0]J[g{
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ku9FN
AND (@OriginalSize * 8 /1024) > @NewSize dzNaow*0&V
BEGIN -- Outer loop. R
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SELECT @Counter = 0 Po!JgcJ#\
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ,
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BEGIN -- update `[ ` *@O(y
INSERT DummyTrans VALUES ('Fill Log') i^ cM@?
DELETE DummyTrans S%s|P=u
SELECT @Counter = @Counter + 1 pD_eo6xX
END p
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EXEC (@TruncLog) Y1_6\zpA
END obc^<ZD]
SELECT 'Final Size of ' + db_name() + ' LOG is ' + C\2 >7
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + UH,4b`b
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' i
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FROM sysfiles FlA\Ad;v
WHERE name = @LogicalFileName y#Za|nt
DROP TABLE DummyTrans lyH X#]
SET NOCOUNT OFF Nw$[a$^n
8、说明:更改某个表 {S"
exec sp_changeobjectowner 'tablename','dbo' 2\CkX
9、存储更改全部表 q'AnI$!
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch M=
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@OldOwner as NVARCHAR(128), ]V769B9
@NewOwner as NVARCHAR(128) ?)o4 Kt'h
AS !_z<W~t"
DECLARE @Name as NVARCHAR(128) nK%/tdq
DECLARE @Owner as NVARCHAR(128) n.Eoi4jV'
DECLARE @OwnerName as NVARCHAR(128) vb. Y8[
DECLARE curObject CURSOR FOR CbH T #
select 'Name' = name, . I&)MZ>n
'Owner' = user_name(uid) c>WpO Z,
from sysobjects g*r{!:,t
where user_name(uid)=@OldOwner VRQbf
order by name G5nj,$F+
OPEN curObject W/ZahPPq
FETCH NEXT FROM curObject INTO @Name, @Owner s8yTK2v2\
WHILE(@@FETCH_STATUS=0) Rr;LV<q+
BEGIN T.w}6?2
if @Owner=@OldOwner E
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begin xX&>5 "
set @OwnerName = @OldOwner + '.' + rtrim(@Name) SL\y\GaV
exec sp_changeobjectowner @OwnerName, @NewOwner ?ZuD
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end lF}$`6
-- select @name,@NewOwner,@OldOwner i h$@:^\
FETCH NEXT FROM curObject INTO @Name, @Owner 5)>ZO)F&
END G0;EbJ/&
close curObject K.iH
deallocate curObject N} x/&e
GO K'{W9~9Lq
10、SQL SERVER中直接循环写入数据 8T.5Mhx0jS
declare @i int #SihedWi
set @i=1 R!V5-0%
while @i<30 U ygw*+
begin w(e+o.:
insert into test (userid) values(@i) jQ_|z@OV
set @i=@i+1 5nxS+`Pn.)
end N9JgV,`
小记存储过程中经常用到的本周,本月,本年函数 Xx y
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Dateadd(wk,datediff(wk,0,getdate()),-1) 8NAWA3^B
Dateadd(wk,datediff(wk,0,getdate()),6) XC/]u%n8](
Dateadd(mm,datediff(mm,0,getdate()),0) ?;r8SowZ7
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) X.T\=dm%v
Dateadd(yy,datediff(yy,0,getdate()),0) (9YYv+GGd*
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) +.gf]|
上面的SQL代码只是一个时间段 sQ>B_Y!
Dateadd(wk,datediff(wk,0,getdate()),-1) b!^M}s6
Dateadd(wk,datediff(wk,0,getdate()),6) RZ<+AX9R
就是表示本周时间段. %+7T9>+
下面的SQL的条件部分,就是查询时间段在本周范围内的: e0|_Z])D
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) UP~WP@0F
而在存储过程中 7k`*u) Q
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) -|k&L}\OB0
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) SN[L4}{