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。 Xca Y'k#
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一、基础 P$.Azrl
1、说明:创建数据库 $2Ox;+
CREATE DATABASE database-name )qD%5} t
2、说明:删除数据库 5bv(J
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drop database dbname kX\t0'=]
3、说明:备份sql server J7emoD[
--- 创建 备份数据的 device O~9
%!LAu
USE master 6YrkS;_HS
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' !y'LKze+G
--- 开始 备份 0 '~Jr\4
BACKUP DATABASE pubs TO testBack 6=90 wu3
4、说明:创建新表 ]s s0~2
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ;:cU /{W
根据已有的表创建新表: ,\[&%ph
A:create table tab_new like tab_old (使用旧表创建新表) 4eYj.=I
B:create table tab_new as select col1,col2... from tab_old definition only R8Lp8!F'
5、说明:删除新表 iYHD:cg)~
drop table tabname =bZ>>-<
6、说明:增加一个列 fV
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Alter table tabname add column col type e<l Wel
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。 C#p$YQf
7、说明:添加主键: Alter table tabname add primary key(col) N+b"LZc
说明:删除主键: Alter table tabname drop primary key(col) :doP66["!
8、说明:创建索引:create [unique] index idxname on tabname(col....) sBu=@8R]y
删除索引:drop index idxname mR[J Xh9s
注:索引是不可更改的,想更改必须删除重新建。 X82sw>Y
9、说明:创建视图:create view viewname as select statement DuZ51[3_L
删除视图:drop view viewname m=PSCIb
10、说明:几个简单的基本的sql语句 odny{ePAf
选择:select * from table1 where 范围 eek5Xm
插入:insert into table1(field1,field2) values(value1,value2) >6=yxCJ
删除:delete from table1 where 范围 KKa"Ba$g
更新:update table1 set field1=value1 where 范围 Bca\grA
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 9,82Uta
排序:select * from table1 order by field1,field2 [desc] ??aOr*%
总数:select count as totalcount from table1 <QugV3e
求和:select sum(field1) as sumvalue from table1 !a~>;+
平均:select avg(field1) as avgvalue from table1 d'kQE_y2.
最大:select max(field1) as maxvalue from table1 ^]Lr_k
最小:select min(field1) as minvalue from table1 7}%3Aw6]S
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11、说明:几个高级查询运算词 %xyt4}-)m
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A: UNION 运算符 JnmJN1@I
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。 nC qUg_{D
B: EXCEPT 运算符 X/];*='Q
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&YYw8&
C: INTERSECT 运算符 !0fpD'f!n
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。 cA`R~o"
注:使用运算词的几个查询结果行必须是一致的。 R5r )01
12、说明:使用外连接 >UE_FC*u
A、left outer join: EW0H"YIC
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{#od
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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 w1rB"rB?
B:right outer join: e~W35Y>A
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。 D+LeZBJ
C:full outer join: yps7MM-r
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。 [O&2!x
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二、提升 u#\=g:
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) x{Gb4=?l
法一:select * into b from a where 1<>1 TRcY!
法二:select top 0 * into b from a :upi2S_e
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) \Z
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insert into b(a, b, c) select d,e,f from b; O:+#k-?
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) <3LyNG.
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 KU"?ZI
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. s)_7*DY
4、说明:子查询(表名1:a 表名2:b) uwyzxj
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) gZM\RJZ_
5、说明:显示文章、提交人和最后回复时间 SM@l4GH
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b x5WFPY$wM
6、说明:外连接查询(表名1:a 表名2:b) -F/"W
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Z$k4T$,[-
7、说明:在线视图查询(表名1:a ) :tedtV~
select * from (SELECT a,b,c FROM a) T where t.a > 1; ^p|MkB?uM
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 FdKp@&O+1
select * from table1 where time between time1 and time2 @%O"P9;s
select a,b,c, from table1 where a not between 数值1 and 数值2 `]FA} wC
9、说明:in 的使用方法 {K09U^JU
select * from table1 where a [not] in ('值1','值2','值4','值6') \d&j`UVY
10、说明:两张关联表,删除主表中已经在副表中没有的信息 bguhx3s
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) M9_
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11、说明:四表联查问题: a,#f%#J\
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... I$n 0aR6
12、说明:日程安排提前五分钟提醒 ..Zuy|?w
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 5:hajXd
13、说明:一条sql 语句搞定数据库分页 aM9^V MOb
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 \%KJ+PJ
14、说明:前10条记录 ' 6Ybf
select top 10 * form table1 where 范围 1wW8D>f]K
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.) x9a*^l
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) %Fa/82:- "
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 t*.O >$[
(select a from tableA ) except (select a from tableB) except (select a from tableC) .YYiUA-i9n
17、说明:随机取出10条数据 PM=Q\0
select top 10 * from tablename order by newid() yXh=~:1~
18、说明:随机选择记录 (i.MxGDd
select newid() ]N*q3 y|)
19、说明:删除重复记录 0F1 a
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) drBWo|/
20、说明:列出数据库里所有的表名 `a["`N^
select name from sysobjects where type='U' lV?rC z
21、说明:列出表里的所有的 )xiic3F
select name from syscolumns where id=object_id('TableName') H\Y.l,^
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。 AZ(["kh[
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 |<\o%89AM
显示结果: 7Z0
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type vender pcs qy`@\)S/5
电脑 A 1 Ih ;6(5z
电脑 A 1 'aBX>M
光盘 B 2 u&I?LZ-=,
光盘 A 2 TKx.`Cf
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手机 B 3 U-QK
手机 C 3 O/e5LA
23、说明:初始化表table1 L
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TRUNCATE TABLE table1 Cl7IP<.
24、说明:选择从10到15的记录 1tDd4r?Y
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc !l?Go<^*L
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三、技巧 nC$f0r"z
1、1=1,1=2的使用,在SQL语句组合时用的较多 ]ctUl#j
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ]!d #2(
如: MOP/ q4j[
if @strWhere !='' >~){KV1~
begin R56:}<Y,
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere _k\*4K8L
end IiHl"2+/
else beRpA;
begin B[F x2r`0
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' R(74Px,/
end M9.jJf
我们可以直接写成 H1yl88K
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere Vk5}d[[l
2、收缩数据库 f$Nz).(
--重建索引 Pp7}|/
DBCC REINDEX |#D3~au
DBCC INDEXDEFRAG Dkayk
--收缩数据和日志 VE+Q Y9(
DBCC SHRINKDB :XxsD D
DBCC SHRINKFILE u>
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3、压缩数据库 +7U$qEG
dbcc shrinkdatabase(dbname) F-R4S^eV
4、转移数据库给新用户以已存在用户权限 ZN~:^,PO/
exec sp_change_users_login 'update_one','newname','oldname' D.kLx@Z
go p[4KN(PyK
5、检查备份集 3 q^3znt
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' %E}f7GT4
6、修复数据库 J(ZYoJ
ALTER DATABASE [dvbbs] SET SINGLE_USER ]OL
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GO -M2c8P:.b
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK <.HX_z3l
GO m=j xTZK
ALTER DATABASE [dvbbs] SET MULTI_USER )[|TxXz
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GO 26B]b{Iz{
7、日志清除 =H%c/Jty
SET NOCOUNT ON - Ob'/d5&
DECLARE @LogicalFileName sysname, _Jx.?8
@MaxMinutes INT, #f0J.)M
@NewSize INT bX6eNk-L
USE tablename -- 要操作的数据库名 2 DJs'"8
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 7m~.V[l1
@MaxMinutes = 10, -- Limit on time allowed to wrap log. \XFF(
@NewSize = 1 -- 你想设定的日志文件的大小(M) `wj<d>m
-- Setup / initialize KC9_H>
DECLARE @OriginalSize int %JeT,{
SELECT @OriginalSize = size 5Mf bO3
FROM sysfiles 5,cq-`
WHERE name = @LogicalFileName J.W0F# ?
SELECT 'Original Size of ' + db_name() + ' LOG is ' + X,y0J
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + qF C0$:z&
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' .|^L\L(!
FROM sysfiles 1v)ur\>R
WHERE name = @LogicalFileName m^Qc9s#D
CREATE TABLE DummyTrans \2KwF}[m
(DummyColumn char (8000) not null) 48vKUAzx`
DECLARE @Counter INT, I(y:Td
@StartTime DATETIME, 4/vQ/>c2j
@TruncLog VARCHAR(255) V]dzKNFi
SELECT @StartTime = GETDATE(), lK;|ciq"c7
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ;|*o^9q
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Xb6X'rY
EXEC (@TruncLog) }K1v=k
-- Wrap the log if necessary. h}r .(MVt
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired U2m86@E
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) m>B^w)&C
AND (@OriginalSize * 8 /1024) > @NewSize B*!{LjXV
BEGIN -- Outer loop. o9&1Ct
SELECT @Counter = 0 G`8i{3:
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) m%hI@'
BEGIN -- update d#xi_L!
INSERT DummyTrans VALUES ('Fill Log') ]awu7}C9Z
DELETE DummyTrans luXcr
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SELECT @Counter = @Counter + 1 M:K5r7Q!yv
END mj:X'BVA
EXEC (@TruncLog) o|u<tuUW
END K,(37Id'
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Kq&b1x
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 1(t{)Z<
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' -i*{8t
FROM sysfiles RG[b+Qjn
WHERE name = @LogicalFileName =kFZ2/P2t(
DROP TABLE DummyTrans u}Kc>/AF
SET NOCOUNT OFF 7vO3+lT/Y;
8、说明:更改某个表 S bI7<_
exec sp_changeobjectowner 'tablename','dbo' uvC ![j^~
9、存储更改全部表 9jW/"
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch M9so3L<N0
@OldOwner as NVARCHAR(128), K,_d/(T4
@NewOwner as NVARCHAR(128) ;|7]%Z}%
AS 3H"bivK
DECLARE @Name as NVARCHAR(128) Iow45R~]
DECLARE @Owner as NVARCHAR(128) 7bJAOJ'_
DECLARE @OwnerName as NVARCHAR(128) s[6y|{&ze
DECLARE curObject CURSOR FOR v3>jXf
select 'Name' = name, -=5]B ;
'Owner' = user_name(uid) 1?+%*uoPX
from sysobjects Q#!|h:K
where user_name(uid)=@OldOwner T6_LiB@
order by name PCKgdh},
OPEN curObject Zw6UH;5
FETCH NEXT FROM curObject INTO @Name, @Owner DvL/xlN
WHILE(@@FETCH_STATUS=0) mz)Z
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BEGIN +9Vp<(
if @Owner=@OldOwner )~@iM.}S2
begin )2vkaR
set @OwnerName = @OldOwner + '.' + rtrim(@Name) p+6L qk<
exec sp_changeobjectowner @OwnerName, @NewOwner P(h[QAM
end BO]}E:C9
-- select @name,@NewOwner,@OldOwner e+416
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FETCH NEXT FROM curObject INTO @Name, @Owner EhJpJb[Z
END -aj) _.d
close curObject ]1YyP
deallocate curObject fbv%&z
GO MYI*0o;
10、SQL SERVER中直接循环写入数据 j!m42
declare @i int >Vp#
set @i=1 A_nu:K-
while @i<30 jiAKV0lX
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begin RC{|:@]8
insert into test (userid) values(@i) y*K]z
set @i=@i+1 .zDm{_'
end |Iq#Q3w
小记存储过程中经常用到的本周,本月,本年函数 )S~ySiJ<U
Dateadd(wk,datediff(wk,0,getdate()),-1) oW7\T!f
Dateadd(wk,datediff(wk,0,getdate()),6) {Ee[rAVGp
Dateadd(mm,datediff(mm,0,getdate()),0) d^-sxl3}
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) _pZ2^OO@
Dateadd(yy,datediff(yy,0,getdate()),0) $/R r|<
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) a[).'$S}'
上面的SQL代码只是一个时间段 ^R;Qa#=2
Dateadd(wk,datediff(wk,0,getdate()),-1) 1uz7E
Dateadd(wk,datediff(wk,0,getdate()),6) EGD&/%aC
就是表示本周时间段. #0*OkZMt
下面的SQL的条件部分,就是查询时间段在本周范围内的: Wbra*LNU
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) bIs@CDB
而在存储过程中 y*6-?@
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) s}m.r5
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) %p wpRD@