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。 O0`o0!=P
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一、基础 B183h
1、说明:创建数据库 Ja4j7d1:
CREATE DATABASE database-name B>]4NF\)H9
2、说明:删除数据库 TUy
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drop database dbname 4,g[g#g<q
3、说明:备份sql server bd'io O
--- 创建 备份数据的 device ZovF]jf k
USE master g"}j
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 9-ei#|Vnt[
--- 开始 备份 V*d@@%u**
BACKUP DATABASE pubs TO testBack nO#a|~-))
4、说明:创建新表 |K.J@zW
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) %]"eN{Uvn
根据已有的表创建新表: n{*A<-vL
A:create table tab_new like tab_old (使用旧表创建新表) {JGXdp:SB
B:create table tab_new as select col1,col2... from tab_old definition only jjJvyZi~J
5、说明:删除新表 $j(laD#AR
drop table tabname }.L:(z^L,Y
6、说明:增加一个列 QgF2f/;!
Alter table tabname add column col type $cSmub ZK
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 }uFV\1
7、说明:添加主键: Alter table tabname add primary key(col) \281X
说明:删除主键: Alter table tabname drop primary key(col) SJ7-lben3
8、说明:创建索引:create [unique] index idxname on tabname(col....) +,q#'wSQG
删除索引:drop index idxname ~rfUqM]I
注:索引是不可更改的,想更改必须删除重新建。 ->9waXRDz)
9、说明:创建视图:create view viewname as select statement R+&{lc
删除视图:drop view viewname NG+%H1!$_
10、说明:几个简单的基本的sql语句 }q?*13iy(
选择:select * from table1 where 范围 >1*Dg?/=S
插入:insert into table1(field1,field2) values(value1,value2) ^ }k qAmr
删除:delete from table1 where 范围 #Fkn-/nL
更新:update table1 set field1=value1 where 范围 2Q;g|*]
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! tNf_,]u
排序:select * from table1 order by field1,field2 [desc] j=kz^o~mH
总数:select count as totalcount from table1 ZCAg)/
求和:select sum(field1) as sumvalue from table1 APUpqY
平均:select avg(field1) as avgvalue from table1 &iTTal.6
最大:select max(field1) as maxvalue from table1 MhDPf]`
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最小:select min(field1) as minvalue from table1 n!?^:5=s
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11、说明:几个高级查询运算词 `p#u9M>
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A: UNION 运算符 O*lMIWx
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。 VJbn/5+P
B: EXCEPT 运算符 U6IvN@
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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。 SO+J5,)HA
C: INTERSECT 运算符 gR76g4|=;
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。 dUc?>#TU
注:使用运算词的几个查询结果行必须是一致的。 3kJ7aBiR<
12、说明:使用外连接 lz:+y/+1
A、left outer join: __Egr@
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。 YgLHp /
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 GswV/V+u
B:right outer join: R+<M"LriR&
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。 =<.h.n
C:full outer join: WqRaD=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。 5E!Wp[^
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二、提升 AVO$R\1YR
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) O_P8OA#|
法一:select * into b from a where 1<>1 fX/k;0l
法二:select top 0 * into b from a QI4a@WB]ok
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 91oAg[@4G
insert into b(a, b, c) select d,e,f from b; ,R*YI
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) &`B
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insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 7J|eL
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 3e?a$~9
4、说明:子查询(表名1:a 表名2:b) \Lz4ZZjSY
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) l0BYv&tu
5、说明:显示文章、提交人和最后回复时间 rodr@
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 4<A+Tf
6、说明:外连接查询(表名1:a 表名2:b) /g\m7m)u
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c !{S HlS
7、说明:在线视图查询(表名1:a ) &eFv~9
select * from (SELECT a,b,c FROM a) T where t.a > 1; *n*po.Xr
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 {SwvUWOf"
select * from table1 where time between time1 and time2 !glGW[r/7
select a,b,c, from table1 where a not between 数值1 and 数值2 "vF7b|I
9、说明:in 的使用方法 @u1mC\G
select * from table1 where a [not] in ('值1','值2','值4','值6') 8;fi1 "F;}
10、说明:两张关联表,删除主表中已经在副表中没有的信息 1z-Q~m@@
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 9$ =o({
11、说明:四表联查问题: -!-1X7v|Fp
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 ..... D {N,7kT
12、说明:日程安排提前五分钟提醒 Stk'|-z
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ]}9D*V
13、说明:一条sql 语句搞定数据库分页 aMO+y91Y(
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 - -ZSl
14、说明:前10条记录 87OX:6
select top 10 * form table1 where 范围 `y*o-St3
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.) ZJ'FZ8Sx
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Uq=!>C8
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 8?[#\KgH1
(select a from tableA ) except (select a from tableB) except (select a from tableC) F2C v,&'
17、说明:随机取出10条数据 )(DX]Tr`
select top 10 * from tablename order by newid() 5@`DS-7h
18、说明:随机选择记录 K)nn;j=
select newid() I`[s(C>3@
19、说明:删除重复记录 e"]DIy4s
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) x0ICpt{;
20、说明:列出数据库里所有的表名 #RTiWD[o
select name from sysobjects where type='U' oF=UjA
21、说明:列出表里的所有的 QmY1Bn?s
select name from syscolumns where id=object_id('TableName') ,7^,\ ,-m
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。 -3|i5,f
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 }^Ky)**
显示结果: }!1pA5x$
type vender pcs Na>?1F"KHk
电脑 A 1 B+n(K+
电脑 A 1 :=2l1Y[-G
光盘 B 2 T]y^PT<8?
光盘 A 2 C^9bur/
手机 B 3 la*c/*
手机 C 3 #2Z\K>L
23、说明:初始化表table1 5u^;71
TRUNCATE TABLE table1 $|H7fn(r
24、说明:选择从10到15的记录 L<O"36R
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc V38v2LI
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三、技巧 rhO8 v
1、1=1,1=2的使用,在SQL语句组合时用的较多 {"@E_{\
"where 1=1" 是表示选择全部 "where 1=2"全部不选, (7?jjH^4
如: I>%@[h,+
if @strWhere !='' {GKq Ou
begin O`2hTY\
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere #_4JTGJ
end
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else ALl0(<u67
begin Z >F5rkJ
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' Fy-|E>@]D
end [LrA_N
我们可以直接写成 L7 g4'
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere >
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2、收缩数据库 ZE"Z_E;r
--重建索引 XE.Y?{,R$
DBCC REINDEX Q??nw^8Hi
DBCC INDEXDEFRAG \
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--收缩数据和日志 Q\{$&0McF
DBCC SHRINKDB a!*K)x,"<
DBCC SHRINKFILE i~;Yrc%AEX
3、压缩数据库 <|c[
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dbcc shrinkdatabase(dbname) r^$WX@ t&
4、转移数据库给新用户以已存在用户权限 $ZfoJR]%
exec sp_change_users_login 'update_one','newname','oldname' :Tn1]a)f6
go c(!8L\69V}
5、检查备份集 EP}NT)z,{
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' F<|x_6a\
6、修复数据库 'qnnZE
ALTER DATABASE [dvbbs] SET SINGLE_USER -40OS=wpA
GO -8D$ [@y(
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK =3<@{^Eg
GO N[8y+2SZ
ALTER DATABASE [dvbbs] SET MULTI_USER ["
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GO ?R\:6x<
7、日志清除 dT4e[4l
SET NOCOUNT ON =~F.7wq*^
DECLARE @LogicalFileName sysname, DTp|he
@MaxMinutes INT, 6n5>{X
@NewSize INT F]7$Y
USE tablename -- 要操作的数据库名 G,JK$j>*l
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 3m59EI-p
@MaxMinutes = 10, -- Limit on time allowed to wrap log. -3eHJccB
@NewSize = 1 -- 你想设定的日志文件的大小(M) )kuw&SH,
-- Setup / initialize E1V;eoK.D
DECLARE @OriginalSize int (#%R'9Rv
SELECT @OriginalSize = size G2e0\}q
FROM sysfiles `Wy8g?d;bn
WHERE name = @LogicalFileName 6<+ 8[o
SELECT 'Original Size of ' + db_name() + ' LOG is ' + (N` x
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + d@0&
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' *m9,_~t
FROM sysfiles 6d#
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WHERE name = @LogicalFileName (v$$`zh
CREATE TABLE DummyTrans s2M|ni=
(DummyColumn char (8000) not null) {rWFgn4Li
DECLARE @Counter INT, &0QtHcXpR
@StartTime DATETIME, ^VAvQ(b!:i
@TruncLog VARCHAR(255) gyAKjLqqpi
SELECT @StartTime = GETDATE(), FQGh+.U
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' _/%,ZoZ2
DBCC SHRINKFILE (@LogicalFileName, @NewSize) SwVdo|%.?
EXEC (@TruncLog) .*+KQA8
-- Wrap the log if necessary. =x3ZQA
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired E#A}J:
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) L fx$M
AND (@OriginalSize * 8 /1024) > @NewSize |"XxM(Dm
BEGIN -- Outer loop. E2a00i/9Y
SELECT @Counter = 0 1X$hwkof
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) _;yi/)-2
BEGIN -- update cp\A
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INSERT DummyTrans VALUES ('Fill Log')
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DELETE DummyTrans p.J+~s4G
SELECT @Counter = @Counter + 1 <4QOjW
END T%p/(
EXEC (@TruncLog) )i{B:w\ ^
END =(U&?1 R4
SELECT 'Final Size of ' + db_name() + ' LOG is ' + c<J/I_!
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + WG?;Z
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' soi.`xE
FROM sysfiles tW#=St0<.o
WHERE name = @LogicalFileName j/Rm~!q
DROP TABLE DummyTrans ZQQ0}
SET NOCOUNT OFF f}U@e0Lsb
8、说明:更改某个表 % HK \
exec sp_changeobjectowner 'tablename','dbo' {Y#$
9、存储更改全部表 rS/}!|uAu
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch >:yU bo)
@OldOwner as NVARCHAR(128), 4:S?m(ah/
@NewOwner as NVARCHAR(128) x&PVsXdt5m
AS ,@*Srrw
DECLARE @Name as NVARCHAR(128) uY'77,G_J
DECLARE @Owner as NVARCHAR(128) i9%cpPrg8
DECLARE @OwnerName as NVARCHAR(128) S0uEz;cE
DECLARE curObject CURSOR FOR !p#+I=
select 'Name' = name, /"*eMe!=
'Owner' = user_name(uid) _>"f&nbO
from sysobjects A]k-bX= s
where user_name(uid)=@OldOwner qq1@v0
order by name Z}*{4V`R
OPEN curObject 1__Mf.A
FETCH NEXT FROM curObject INTO @Name, @Owner $7bl,~Z
WHILE(@@FETCH_STATUS=0) TaN]{k
BEGIN M~+T
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if @Owner=@OldOwner rS3* k3
begin S66..sa
set @OwnerName = @OldOwner + '.' + rtrim(@Name) {~RS$ |
exec sp_changeobjectowner @OwnerName, @NewOwner b\^q9fy
end _~_E(rTn
-- select @name,@NewOwner,@OldOwner `[*n UdG
FETCH NEXT FROM curObject INTO @Name, @Owner Yo$
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END Q1yj+)_
close curObject $JTQA
deallocate curObject *He%%pk
GO "o
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10、SQL SERVER中直接循环写入数据 erC )2{m
declare @i int 0nbQKoF
set @i=1 *>,CG:`D
while @i<30 hn@T ]k
begin D^~G(m;-
insert into test (userid) values(@i) 8w|-7$ v
set @i=@i+1 8^FAeV#
end F3L'f2yBG
小记存储过程中经常用到的本周,本月,本年函数 klKd !
Dateadd(wk,datediff(wk,0,getdate()),-1) u{_jweZ
Dateadd(wk,datediff(wk,0,getdate()),6) QIg.r\>o
Dateadd(mm,datediff(mm,0,getdate()),0) ;}BDEBl
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) DfJHH)Ry}
Dateadd(yy,datediff(yy,0,getdate()),0) E3a^)S{
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 609_ZW;)
上面的SQL代码只是一个时间段 5lc%GJybV
Dateadd(wk,datediff(wk,0,getdate()),-1) FNyr0!t,
Dateadd(wk,datediff(wk,0,getdate()),6) Bh\>2]~@a
就是表示本周时间段. ;HPQhN_
下面的SQL的条件部分,就是查询时间段在本周范围内的: <7;AK!BH
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) J0eJRs
而在存储过程中 =Q!)xEK
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) >){"x(4`
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) /QeJ#EHn