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。 @Z<Z//^k
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一、基础 4"\%/kG
1、说明:创建数据库 $|AasT5w
CREATE DATABASE database-name 6LabFX@{&
2、说明:删除数据库 7'|aEH
drop database dbname t8*NldC
3、说明:备份sql server }?sC1]-j&
--- 创建 备份数据的 device EIPX q
USE master y43ha
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' v
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--- 开始 备份 a`LkP%
BACKUP DATABASE pubs TO testBack D?4bp'0 3
4、说明:创建新表 4EaxU !BT
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ieXi6^M$
根据已有的表创建新表: 8uA!Vrp3
A:create table tab_new like tab_old (使用旧表创建新表) Jw{duM;]
B:create table tab_new as select col1,col2... from tab_old definition only #RHt;SFx
5、说明:删除新表 6r`Xi&
drop table tabname 4I*'(6
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6、说明:增加一个列 1had8K-
Alter table tabname add column col type fm
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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。 NB-%Tp*d
7、说明:添加主键: Alter table tabname add primary key(col) R{Cbp=3J
说明:删除主键: Alter table tabname drop primary key(col) y>^0q/=]?O
8、说明:创建索引:create [unique] index idxname on tabname(col....) 2W#^^4^+
删除索引:drop index idxname SnM^T(gtS3
注:索引是不可更改的,想更改必须删除重新建。 @7{.err!
9、说明:创建视图:create view viewname as select statement ,
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删除视图:drop view viewname aDu[iaZ
10、说明:几个简单的基本的sql语句 n98sY+$-z
选择:select * from table1 where 范围 ^$[iLX
插入:insert into table1(field1,field2) values(value1,value2) YWL7.Y>%5
删除:delete from table1 where 范围 8i)9ho<
更新:update table1 set field1=value1 where 范围 z|\n^ZK=
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 1X9J[5|ll
排序:select * from table1 order by field1,field2 [desc] ^1_CS*
总数:select count as totalcount from table1 [\&2&
求和:select sum(field1) as sumvalue from table1 lR]FQnZ
平均:select avg(field1) as avgvalue from table1 @|e
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最大:select max(field1) as maxvalue from table1 kU.@HJ[@j
最小:select min(field1) as minvalue from table1 =T1Xfib
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11、说明:几个高级查询运算词 Ty7)j]b"zl
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A: UNION 运算符 2IGU{&s
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。 s d = bw
B: EXCEPT 运算符 m)Wq*&,o
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。 Jm"W+! E
C: INTERSECT 运算符 Hx!eCTO:*
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。 jBl$r{L
注:使用运算词的几个查询结果行必须是一致的。 gAf4wq
12、说明:使用外连接 !T
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A、left outer join: 8~&=vc
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 6?[SlPPE1
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ,LDL%<7t
B:right outer join: @Bn4ZFB@
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 m;L3c(r.
C:full outer join: 7xYz9r)w`
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 )g}G{9M^
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二、提升 I&<'A[vHl
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 1aUg({
法一:select * into b from a where 1<>1 b~@+6?
法二:select top 0 * into b from a +@*>N;$
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ]'$:Y
insert into b(a, b, c) select d,e,f from b; 0G2Y_A&e**
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) -Kcjnl92i
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 9}Ge@a<j
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. s)KlKh
4、说明:子查询(表名1:a 表名2:b) 4t3>`x
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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) s!>9od6^
5、说明:显示文章、提交人和最后回复时间 W=OryEV?
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b +;M 5Sp
6、说明:外连接查询(表名1:a 表名2:b) 0)ZLdF_6
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Qqk(,1u
7、说明:在线视图查询(表名1:a ) iSg0X8J)
select * from (SELECT a,b,c FROM a) T where t.a > 1; Q{an[9To~P
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 T8x8TN"
select * from table1 where time between time1 and time2 1kR. .p<"
select a,b,c, from table1 where a not between 数值1 and 数值2 IM5[O}aq
9、说明:in 的使用方法 g:GywXW
select * from table1 where a [not] in ('值1','值2','值4','值6') ZSyXzop
10、说明:两张关联表,删除主表中已经在副表中没有的信息 |f!J-H)
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) &0fV;%N
11、说明:四表联查问题: &xGpbJG
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 ..... #M5d,%?+#[
12、说明:日程安排提前五分钟提醒 5?([jAOf
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 H4j1yD(d
13、说明:一条sql 语句搞定数据库分页 #9~,d<H
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 O f-xGoYZ
14、说明:前10条记录 S.q0L
select top 10 * form table1 where 范围 bOp%
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.) P ?nk>
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) gsl_aW!
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 ;%^{Zybh
(select a from tableA ) except (select a from tableB) except (select a from tableC) !hHX8TD^J
17、说明:随机取出10条数据 0,Ib74N'w
select top 10 * from tablename order by newid() .yFO]
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18、说明:随机选择记录 KWAd~8,mk
select newid() oe0YxSauL
19、说明:删除重复记录 Q]3]Z/i
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) =1'WZp}D5
20、说明:列出数据库里所有的表名 bf{_U%`
select name from sysobjects where type='U' 9)o@d`*
21、说明:列出表里的所有的 FK`:eP{
select name from syscolumns where id=object_id('TableName') zmL
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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。 YMU""/(
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 v~jm<{={g
显示结果: dQ9W40g1
type vender pcs 1eEML"
电脑 A 1 }pnp._j
电脑 A 1 z(
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光盘 B 2 -;FAS3(wy
光盘 A 2 <5P*uZ
手机 B 3 5h0Hk<N
手机 C 3 5X>~39(r
23、说明:初始化表table1 \NEk B&^n
TRUNCATE TABLE table1 )+=Kh$VbS
24、说明:选择从10到15的记录 Z @ef2y;
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ;[[6[i
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三、技巧 jb{9W7;RL
1、1=1,1=2的使用,在SQL语句组合时用的较多 *'aouS/?<6
"where 1=1" 是表示选择全部 "where 1=2"全部不选, dU2;
如: !`1m.
if @strWhere !='' O:pg+o&
begin |v5
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ~I%164B+/
end NGkxg:
else =&qH%S6
begin >5"e<mwD7d
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' E)f9`][
end gA}<Y
我们可以直接写成 4VwMl)8ic
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere S]~5iO_bst
2、收缩数据库 b18f=<#
--重建索引 j3T)gFP
DBCC REINDEX 2FV@?x0po
DBCC INDEXDEFRAG ZGsd cnz
--收缩数据和日志 o0S8ki
DBCC SHRINKDB %*wEzvt*
DBCC SHRINKFILE HW,v"
3、压缩数据库 x?0K'
dbcc shrinkdatabase(dbname) l^B4.1rT
4、转移数据库给新用户以已存在用户权限 )pT5"{
exec sp_change_users_login 'update_one','newname','oldname' ;aX?K/
go \%.oi@A
5、检查备份集 )*{B_[
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Sy4|JM-5
6、修复数据库 #s15AyKz5
ALTER DATABASE [dvbbs] SET SINGLE_USER 3 H5
GO _)!*,\*`{
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK QjG/H0*mP
GO D %)L"5C
ALTER DATABASE [dvbbs] SET MULTI_USER ~{5va
GO nvXjW@)`
7、日志清除
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SET NOCOUNT ON {;& U5<NO
DECLARE @LogicalFileName sysname, Y~A I2H S
@MaxMinutes INT, Az8ZA ~Op=
@NewSize INT QV:> x#=V
USE tablename -- 要操作的数据库名 SE@TY32T
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 OdY9g2y#m
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 3o/f, }_
@NewSize = 1 -- 你想设定的日志文件的大小(M) R){O]<+
-- Setup / initialize 8>6<GdGL<n
DECLARE @OriginalSize int "kBVHy
SELECT @OriginalSize = size ID!S}D
FROM sysfiles <)T~_s
WHERE name = @LogicalFileName _@[W[=|H
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 6
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + U` HY
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' |9IOZ>H9
FROM sysfiles l&e$:=;8
WHERE name = @LogicalFileName Ba|}$jo
CREATE TABLE DummyTrans q*`
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(DummyColumn char (8000) not null) qQG? k~r
DECLARE @Counter INT, Y,Rr[i"j
@StartTime DATETIME, BG?>)]6
@TruncLog VARCHAR(255) W|2| v?v
SELECT @StartTime = GETDATE(), 7Re\*[)T
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' CMOyK^(e
DBCC SHRINKFILE (@LogicalFileName, @NewSize) CM++:Y vJ
EXEC (@TruncLog) lqJ92vi6Q
-- Wrap the log if necessary. yt5<J-m
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired eI2HTFyT
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 9X;*GC;d
AND (@OriginalSize * 8 /1024) > @NewSize ]H}2|~c
BEGIN -- Outer loop. aGi`(|shW
SELECT @Counter = 0 'ROz| iJ
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ?Z?(ky!
BEGIN -- update x 4L3Z__
INSERT DummyTrans VALUES ('Fill Log') q{f\_2[
DELETE DummyTrans RJerx:]
SELECT @Counter = @Counter + 1 hCr,6nc C
END /_{ZWLi(
EXEC (@TruncLog) EK"/4t{L_
END 0;">ETh=
SELECT 'Final Size of ' + db_name() + ' LOG is ' + at@tS>Dv
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + R#;xBBt8
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' &?H$-r1/?V
FROM sysfiles 7Vh
WHERE name = @LogicalFileName BSgT
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DROP TABLE DummyTrans S\:+5}
SET NOCOUNT OFF w?|qKO
8、说明:更改某个表 ;
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exec sp_changeobjectowner 'tablename','dbo' g@4~,
9、存储更改全部表 :?g+\:`/0j
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ,@?9H ~\
@OldOwner as NVARCHAR(128), rXD:^wUSc
@NewOwner as NVARCHAR(128) ,h'Q
AS 9wldd*r
DECLARE @Name as NVARCHAR(128) e"eIQI|N
DECLARE @Owner as NVARCHAR(128) :}Yk0*
DECLARE @OwnerName as NVARCHAR(128) Hv,ll1@h
DECLARE curObject CURSOR FOR {2P18&=
select 'Name' = name, qmFbq<&
'Owner' = user_name(uid) .nrbd#i-
from sysobjects Z.Z;p/4F
where user_name(uid)=@OldOwner 6LGl]jHf
order by name o ^UOkxs.
OPEN curObject Sqb>aj
FETCH NEXT FROM curObject INTO @Name, @Owner Komdz/g
WHILE(@@FETCH_STATUS=0) }s<;YC
BEGIN z7`|N`$Z#s
if @Owner=@OldOwner NFEr ,n
begin iz`>'wpC
set @OwnerName = @OldOwner + '.' + rtrim(@Name) `H$XO{w
exec sp_changeobjectowner @OwnerName, @NewOwner s_fe4K
end *#Ia8^z=p
-- select @name,@NewOwner,@OldOwner m+s*Io{Ip
FETCH NEXT FROM curObject INTO @Name, @Owner ~B"HI+:\L
END ut560,h~
close curObject .qZz'Eq[
deallocate curObject kG!hqj
GO klFS3G
10、SQL SERVER中直接循环写入数据 (ub(0 h0j
declare @i int l~]] RgU
set @i=1 *(q?O_3,b
while @i<30 SF-"3M
begin cRrJZ9
insert into test (userid) values(@i) M3@qhEf?vk
set @i=@i+1 s<!G2~T
end w[gt9]}N
小记存储过程中经常用到的本周,本月,本年函数 ;iKtv+"
Dateadd(wk,datediff(wk,0,getdate()),-1) sZ&|omN
Dateadd(wk,datediff(wk,0,getdate()),6) S8/~'<out
Dateadd(mm,datediff(mm,0,getdate()),0) H(76sE
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ]zJO)(d$>
Dateadd(yy,datediff(yy,0,getdate()),0) 54>0Dv??H
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) c]#}#RJ`\
上面的SQL代码只是一个时间段 *.>@
Dateadd(wk,datediff(wk,0,getdate()),-1) W&
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Dateadd(wk,datediff(wk,0,getdate()),6) +O 7(
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就是表示本周时间段. ;#v3C;
下面的SQL的条件部分,就是查询时间段在本周范围内的: bs~P
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) C@`#@1X
而在存储过程中 Icg-rwa<Z
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) K\U`gTGc
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) {*GBUv5