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。 a>6M{C@pd
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一、基础 ~U ]%>Zf
1、说明:创建数据库 ]A+t@/k
CREATE DATABASE database-name EronNtu8i
2、说明:删除数据库 X=Y(,ZR(&
drop database dbname o8A8fHl
3、说明:备份sql server wvxqgXnB\
--- 创建 备份数据的 device KB~`3Wj|Z
USE master *ni0.
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' " :[;}f;
--- 开始 备份 ,s}7KE
BACKUP DATABASE pubs TO testBack 1j}e2H
4、说明:创建新表 8MU7|9 Q
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) BHkicb ?
根据已有的表创建新表: @C('kUX~!
A:create table tab_new like tab_old (使用旧表创建新表) !6#.%"{-
B:create table tab_new as select col1,col2... from tab_old definition only juu"V]Q1
5、说明:删除新表 q{[y4c1bG{
drop table tabname gtY7N>e
6、说明:增加一个列 4Pf"R~&[
Alter table tabname add column col type OzH\YN
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。 kA2)T,s74
7、说明:添加主键: Alter table tabname add primary key(col) P= E10
说明:删除主键: Alter table tabname drop primary key(col) TL-ALtG
8、说明:创建索引:create [unique] index idxname on tabname(col....) KZ=5"a
删除索引:drop index idxname V.+a}J=Cw
注:索引是不可更改的,想更改必须删除重新建。 Fy>g*3
9、说明:创建视图:create view viewname as select statement E3x<o<v
删除视图:drop view viewname :a=]<_*x
10、说明:几个简单的基本的sql语句 !WB3%E,I
选择:select * from table1 where 范围 >*|Eyv_
插入:insert into table1(field1,field2) values(value1,value2) *Hv d
删除:delete from table1 where 范围 Pc+,iK>
更新:update table1 set field1=value1 where 范围 zQGj,EAM}
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! qM>Dt
排序:select * from table1 order by field1,field2 [desc] W3X;c*j
总数:select count as totalcount from table1 0N6 X;M{zh
求和:select sum(field1) as sumvalue from table1 qr*e9Uk^
平均:select avg(field1) as avgvalue from table1 HuxvIg
最大:select max(field1) as maxvalue from table1 'I[xZu/8yg
最小:select min(field1) as minvalue from table1 ^R+CkF4l l
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11、说明:几个高级查询运算词 \pI
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A: UNION 运算符 cvpZF5mL]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。 Sx_j`Cgy
B: EXCEPT 运算符 n@oSLo`k,`
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。 ~(cqFf
C: INTERSECT 运算符 u b@'(*
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。 %7Gq#rq
注:使用运算词的几个查询结果行必须是一致的。 n*~#]%4
12、说明:使用外连接 v=IcVHuf
A、left outer join: '?$<k@mJW
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 iZ(p]0aP7
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c X(]J\?n'
B:right outer join: Hjy4tA7,l
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 |A H@W#7j
C:full outer join: I%0J=V;o{
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 /DSy/p0%
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二、提升 1fh6A`c
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) k{\a_e`
法一:select * into b from a where 1<>1 !Ome;gS)
法二:select top 0 * into b from a T
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) "N=q>jaX
insert into b(a, b, c) select d,e,f from b; Ak\"C4s
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) tkdyR1-
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ve*6WDK,H
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. !j0iLYo(*
4、说明:子查询(表名1:a 表名2:b) `u8=~]rblj
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) cdfnM% `>\
5、说明:显示文章、提交人和最后回复时间 MV?sr[V-oP
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b T(*A0
6、说明:外连接查询(表名1:a 表名2:b) >DR/lBtL
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c pf_`{2.\uO
7、说明:在线视图查询(表名1:a ) &$pA,Gjin\
select * from (SELECT a,b,c FROM a) T where t.a > 1; JU-eoB}m
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 +L}R|ihkI
select * from table1 where time between time1 and time2 9!vimu)
select a,b,c, from table1 where a not between 数值1 and 数值2 rj;~SC{
9、说明:in 的使用方法 !%G;t$U=M
select * from table1 where a [not] in ('值1','值2','值4','值6') -"n8Wv
10、说明:两张关联表,删除主表中已经在副表中没有的信息 g);.".@"
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ?B:],aztf
11、说明:四表联查问题: 8)&J oPN
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... x/#.%Ga#T
12、说明:日程安排提前五分钟提醒 M
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SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 Z-z(SKL
13、说明:一条sql 语句搞定数据库分页 U{-[lpd
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段
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14、说明:前10条记录 |>=\
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select top 10 * form table1 where 范围 A,GJ6qp3
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) o(Ro/U(Wu
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) z%WOv~8~
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 { :_qa |
(select a from tableA ) except (select a from tableB) except (select a from tableC) %J|xPp)
17、说明:随机取出10条数据 +Ram%"Zwh
select top 10 * from tablename order by newid() wHhIa3_v
18、说明:随机选择记录 2dBjc{
select newid() )N]%cO(^
19、说明:删除重复记录 azpXE
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Hbz,3{o5
20、说明:列出数据库里所有的表名 *uZ'MS
select name from sysobjects where type='U' lyrwm{&
21、说明:列出表里的所有的 o|c"W}W
select name from syscolumns where id=object_id('TableName') cjBHczkY
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 F5f1j]c
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type AV["%$:
显示结果: 7:h_U9Za?$
type vender pcs ?nx
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电脑 A 1 Q02:qn?T
电脑 A 1 PhC{Gg
光盘 B 2 ~dj4Q
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光盘 A 2 .2STBh.;
手机 B 3 5%(xZ
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手机 C 3 B?<Z(d7
23、说明:初始化表table1 OL$^7FB
TRUNCATE TABLE table1 %Z6\W;
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24、说明:选择从10到15的记录 D
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select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc X+k`UM~
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三、技巧 p9$=."5
1、1=1,1=2的使用,在SQL语句组合时用的较多 r$.v"Wh)
"where 1=1" 是表示选择全部 "where 1=2"全部不选, )v?-[
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如: 9 k>=y n
if @strWhere !='' @IwVR
begin w*s#=]6
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere T~'9p`IW
end wC[Bh^]
else ;P4tqY@
begin y[@<goT
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' dd%-bI^
end -#?p16qz5
我们可以直接写成 (KxL*gB
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere HR83{B21
2、收缩数据库 !56gJJ-r
--重建索引 nob^
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DBCC REINDEX B>&eciY
DBCC INDEXDEFRAG )vFZl]
--收缩数据和日志 pJ 1Q~tI
DBCC SHRINKDB 35[8XD
DBCC SHRINKFILE +tXOP|X
3、压缩数据库 :{v:sK
dbcc shrinkdatabase(dbname) 8oj-5|ct
4、转移数据库给新用户以已存在用户权限 MrA&xM
exec sp_change_users_login 'update_one','newname','oldname' ;|LS$O1c
go O$=)
5、检查备份集 Vhs:X~=qL
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' o[!g,Gmoh
6、修复数据库 d>Z{TFY
ALTER DATABASE [dvbbs] SET SINGLE_USER oGLSk(T&I
GO cKX6pG
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ,e
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GO .baS
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ALTER DATABASE [dvbbs] SET MULTI_USER 7^~pOFdH
GO k'BLos1W
7、日志清除 E5M*Gs
SET NOCOUNT ON z.[ Ok
DECLARE @LogicalFileName sysname, RkJ\?
@MaxMinutes INT, ;Db89Nc$
@NewSize INT 1&
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USE tablename -- 要操作的数据库名 3a4 ]{
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 8F<Qc*'
@MaxMinutes = 10, -- Limit on time allowed to wrap log. X3:-+]6,d
@NewSize = 1 -- 你想设定的日志文件的大小(M) j]"Yzt~u
-- Setup / initialize UP]J`\$o
DECLARE @OriginalSize int m GWT</=[$
SELECT @OriginalSize = size "l&sDh%Lk<
FROM sysfiles &0
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WHERE name = @LogicalFileName {=,?]Z+
SELECT 'Original Size of ' + db_name() + ' LOG is ' + rY>{L6d
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 15r<n
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' `
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FROM sysfiles Iy](?b
WHERE name = @LogicalFileName E$FXs~a
CREATE TABLE DummyTrans `oh'rm3'8
(DummyColumn char (8000) not null) $s hlNW\
DECLARE @Counter INT, zy#E qv
@StartTime DATETIME, gTR:9E:B
@TruncLog VARCHAR(255) NDRk%_Eu(
SELECT @StartTime = GETDATE(), dxkXt k
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' &Sc}3UI/F
DBCC SHRINKFILE (@LogicalFileName, @NewSize) c(bh i
EXEC (@TruncLog) y= ILA
-- Wrap the log if necessary. 3Nh;^
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 9`)NFy?
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) w>X33Ff]8@
AND (@OriginalSize * 8 /1024) > @NewSize AO'B p5:Q
BEGIN -- Outer loop. ?|:!PF*L~z
SELECT @Counter = 0 Uc}L/ax
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) mV;Egm{A\
BEGIN -- update ~R) Km`t
INSERT DummyTrans VALUES ('Fill Log') S[NV-)r=
DELETE DummyTrans oS$&jd
SELECT @Counter = @Counter + 1 oj<.axA,
END ]P ->xJ
EXEC (@TruncLog) m\4jiR_o
END $Tq-<FbM)
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 2&]UFg:8Q
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + EG0NikT?
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Gr#p QE2;
FROM sysfiles UsYH#?|O
WHERE name = @LogicalFileName 5RTAM
DROP TABLE DummyTrans oa`,|dA"
SET NOCOUNT OFF /+J?Ep(_
8、说明:更改某个表 F#iLMO&Q
exec sp_changeobjectowner 'tablename','dbo' b9OT~i=S|
9、存储更改全部表 y6;'?.Y1
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Gz!72H
@OldOwner as NVARCHAR(128), -^;G^Uq6=
@NewOwner as NVARCHAR(128) )j@k[}R#g
AS `ivr$b#
DECLARE @Name as NVARCHAR(128) m7e$Z
DECLARE @Owner as NVARCHAR(128) d <qbUk3;
DECLARE @OwnerName as NVARCHAR(128) "aP>}5<h
DECLARE curObject CURSOR FOR E+"INX7
select 'Name' = name, @}x)>tqD
'Owner' = user_name(uid) bsPw Tp^
from sysobjects 1(!QutEb
where user_name(uid)=@OldOwner [ WZ<d^L
order by name G_[|N>
OPEN curObject *Yvfp{B
FETCH NEXT FROM curObject INTO @Name, @Owner $Kb-mFR
WHILE(@@FETCH_STATUS=0) ^C):yxNP
BEGIN }k<b)I*A
if @Owner=@OldOwner R8\y|p#c
begin _e8@y{/~Fd
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ?YgK]IxD
exec sp_changeobjectowner @OwnerName, @NewOwner 4\2p8__
end \Ul*Nsw
-- select @name,@NewOwner,@OldOwner akBR"y:~:H
FETCH NEXT FROM curObject INTO @Name, @Owner rEdr8qw
END Cz?N[dhh
close curObject 60teD>Eh,
deallocate curObject kzns:-a
GO ss,t[`AV{
10、SQL SERVER中直接循环写入数据 w_,.
declare @i int uiE9#G
set @i=1 1w+&Y;d|
while @i<30 5]p>&|Ud
begin L|6c lGp
insert into test (userid) values(@i) JeUFCWm
set @i=@i+1 aiw~4ix
end nf/iZ &
小记存储过程中经常用到的本周,本月,本年函数 %nOBs ln
Dateadd(wk,datediff(wk,0,getdate()),-1) tJ.LPgfZ
Dateadd(wk,datediff(wk,0,getdate()),6) / vje='[!
Dateadd(mm,datediff(mm,0,getdate()),0)
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Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) p4Vw`i+DnH
Dateadd(yy,datediff(yy,0,getdate()),0)
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) D}cq_|mmn[
上面的SQL代码只是一个时间段 G5=(3 V%
Dateadd(wk,datediff(wk,0,getdate()),-1) 1(hgSf1WH
Dateadd(wk,datediff(wk,0,getdate()),6) qJ"dkT*
就是表示本周时间段. 9qwVBu ;
下面的SQL的条件部分,就是查询时间段在本周范围内的: -1S+fUkiK/
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) {
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而在存储过程中 j^iH[pN] \
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) L\ _8}\
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ^bL.|vB