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。 e>P>DmlW
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一、基础 m;0ZV%c*j
1、说明:创建数据库 h@TP=
CREATE DATABASE database-name :sttGXQX
2、说明:删除数据库 q0b*#j
drop database dbname DPkH:X
3、说明:备份sql server yY]E~
--- 创建 备份数据的 device `fE'$2
USE master i1K$~
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' G=LK
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--- 开始 备份 lh6N3d
BACKUP DATABASE pubs TO testBack q8H nPXV
4、说明:创建新表 d5`D[,]d
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) _T_} k:&X
根据已有的表创建新表: ght3#
A:create table tab_new like tab_old (使用旧表创建新表) y8Rq2jI;(e
B:create table tab_new as select col1,col2... from tab_old definition only csA-<}S5]b
5、说明:删除新表 @1 i<=r
drop table tabname Ro;I%j
6、说明:增加一个列 R:rols"QM
Alter table tabname add column col type @<&u;8y-Cn
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。 o$Y#C{wC%
7、说明:添加主键: Alter table tabname add primary key(col) c7.M\f P
说明:删除主键: Alter table tabname drop primary key(col) >hzSd@J&
8、说明:创建索引:create [unique] index idxname on tabname(col....) zRgAmX/g
删除索引:drop index idxname r7^v@
注:索引是不可更改的,想更改必须删除重新建。 L2wX?NA
9、说明:创建视图:create view viewname as select statement clk]JA (
删除视图:drop view viewname n}-
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10、说明:几个简单的基本的sql语句 y.-Kqa~
选择:select * from table1 where 范围 c|K:oi,z
插入:insert into table1(field1,field2) values(value1,value2) 2%*\XPt)
删除:delete from table1 where 范围 a}iP +#;
更新:update table1 set field1=value1 where 范围 zFQm3 !.
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! oArXP\#
排序:select * from table1 order by field1,field2 [desc] B*9?mcP\
总数:select count as totalcount from table1 u\"/EaQ{
求和:select sum(field1) as sumvalue from table1 `2]TPaWGh
平均:select avg(field1) as avgvalue from table1 /}
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最大:select max(field1) as maxvalue from table1 #$]8WSl
最小:select min(field1) as minvalue from table1 ou{V/?rb
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11、说明:几个高级查询运算词 s< Fp17
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A: UNION 运算符 `Y^l.%AZZ
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。 SbQ:vAE*ho
B: EXCEPT 运算符 V(g5Gn?
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。 `5"3Cj"M
C: INTERSECT 运算符 drvrj~o:
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。 m4yWhUi(o
注:使用运算词的几个查询结果行必须是一致的。 x0K#-
12、说明:使用外连接 HKIr?
A、left outer join: Q#*R({)GH
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。 Z>l<.T"t'
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 FGhnK'
B:right outer join: A~^x*#q{4
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。 NNwGRoDco
C:full outer join: 4TYtgP1
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。 j WMTQLE.
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二、提升 =LgMG^@mu
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) s%8,'3&
法一:select * into b from a where 1<>1 8'NT_NPNb
法二:select top 0 * into b from a
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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) -f1lu*3\
insert into b(a, b, c) select d,e,f from b; i r'C(zD=
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) \(&&ed:
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 cmAdQ)(Kzd
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. <_]W1V:0
4、说明:子查询(表名1:a 表名2:b) 9M;Y$Z
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) M?o_J4
5、说明:显示文章、提交人和最后回复时间 `~=NBN=tiL
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b zbGZ\pz
6、说明:外连接查询(表名1:a 表名2:b) ;lSsy
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c N1.fV -
7、说明:在线视图查询(表名1:a ) -F 9xPw
select * from (SELECT a,b,c FROM a) T where t.a > 1; h0HK~S#xBv
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ~|N,{GaL
select * from table1 where time between time1 and time2 Rg+#(y
select a,b,c, from table1 where a not between 数值1 and 数值2 5:#|Op N
9、说明:in 的使用方法 9MQjSNYzo
select * from table1 where a [not] in ('值1','值2','值4','值6') {+[Ex2b$
10、说明:两张关联表,删除主表中已经在副表中没有的信息 j(}pUV B
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) WF_QhKW|k
11、说明:四表联查问题: _Vf>>tuW
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 ..... l ?YO!$
12、说明:日程安排提前五分钟提醒 E|jU8qz>P
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 l2YA/9.
13、说明:一条sql 语句搞定数据库分页 ,?HM5c{'[Y
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 ) jt?X}
14、说明:前10条记录 0c8_&
select top 10 * form table1 where 范围 TP~1-(M)}
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.) xE$lx:C"FU
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) K-K>'T9F}
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 fVVD}GM=
(select a from tableA ) except (select a from tableB) except (select a from tableC) P,xJVo\
17、说明:随机取出10条数据 =BJe}AV
select top 10 * from tablename order by newid() bTZ.y.sI
18、说明:随机选择记录 atmW? Z
select newid() .:GOKyr(~
19、说明:删除重复记录 #{^qBP[
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) dV16'
20、说明:列出数据库里所有的表名 .p?SPR
select name from sysobjects where type='U' qQ6@43TC
21、说明:列出表里的所有的 cSNeWJKA6
select name from syscolumns where id=object_id('TableName') 4i5b.bU$
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。 |sl^4'Ghc
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 3+vVdvu%
显示结果: rvK%m_r
type vender pcs 8j :=D!S
电脑 A 1 K
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电脑 A 1 v(=0hY9
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光盘 B 2 g!o2vTt5
光盘 A 2 ,V^$Meh
手机 B 3 ^".6~{
手机 C 3 A zp!;+
23、说明:初始化表table1 ULgp]IS
TRUNCATE TABLE table1 [hk/Rp7{
24、说明:选择从10到15的记录 %Pj}
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ~*UY[!+4^=
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三、技巧 tmM; Z(9t
1、1=1,1=2的使用,在SQL语句组合时用的较多 Y> ATL
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 3-)}.8F
如: uPxjW"M+
if @strWhere !='' g5u4|+70
begin LafBf6wds
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 12_7UWZ"
end 8G9( )UF.
else %+<1X?;,Fq
begin #};Zgixo$
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' };EB[n
end jW-;Y/S
我们可以直接写成 412E7
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere hE$3l+
2、收缩数据库 |JP'j1 Ka
--重建索引 e@ $|xa")
DBCC REINDEX oA7| s1
DBCC INDEXDEFRAG N
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--收缩数据和日志 Zy8tI#
DBCC SHRINKDB 5zkj;?s
DBCC SHRINKFILE b&
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3、压缩数据库 bd% M.,
dbcc shrinkdatabase(dbname) $bfmsCcHL
4、转移数据库给新用户以已存在用户权限 +dRRMyxe4
exec sp_change_users_login 'update_one','newname','oldname' 5J1a8RBR
go +Ar4X-A{y
5、检查备份集 K[
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' +DR{aX/ll
6、修复数据库 1oQbV`P
ALTER DATABASE [dvbbs] SET SINGLE_USER {6wXDZxv
GO (TO<SY3AB
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK W:6#0b"_#
GO 0>]&9'cn
ALTER DATABASE [dvbbs] SET MULTI_USER -m mQ]'.0
GO kC6Y?g
7、日志清除 4FZ/~Y1}
SET NOCOUNT ON H@~tJ\L
DECLARE @LogicalFileName sysname, gs0`nysM#
@MaxMinutes INT,
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@NewSize INT `Mcg&Mi~
USE tablename -- 要操作的数据库名 qPWf=s7!
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 :}/\hz
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@MaxMinutes = 10, -- Limit on time allowed to wrap log. LP'q$iB!
@NewSize = 1 -- 你想设定的日志文件的大小(M) ^N
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-- Setup / initialize g)D@4RM
DECLARE @OriginalSize int [z+YXs!N
SELECT @OriginalSize = size ^tWSu?9
FROM sysfiles 6d2eWS
WHERE name = @LogicalFileName *.+F]-
SELECT 'Original Size of ' + db_name() + ' LOG is ' + _`0DO4IU
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + }d iE'
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' %L7DC`
FROM sysfiles w(t1m]pF[
WHERE name = @LogicalFileName JO&RuAq
CREATE TABLE DummyTrans w'VuC82SZ
(DummyColumn char (8000) not null) U5@B7v1
DECLARE @Counter INT, ITi#p%
@StartTime DATETIME, O,
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@TruncLog VARCHAR(255) 4mEJu
SELECT @StartTime = GETDATE(), /BvMNKb$$
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' TcJJ"[0
DBCC SHRINKFILE (@LogicalFileName, @NewSize) #F2DEo^0
EXEC (@TruncLog) burSb:JF
-- Wrap the log if necessary. kM=&Tfpj
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 6Yt3Oq<U
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) NLYf
AND (@OriginalSize * 8 /1024) > @NewSize pS7y3(_
BEGIN -- Outer loop. 61OlnmvE
SELECT @Counter = 0 @\xEK5 SG
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) }1+2&Ps50
BEGIN -- update 5J&Gc;[p
INSERT DummyTrans VALUES ('Fill Log') _5O~]}
DELETE DummyTrans XFl&(I4tB
SELECT @Counter = @Counter + 1 :?m"kh
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END C=U4z|Ym
EXEC (@TruncLog) A&%7Z^Pp
END SkVah:cF-
SELECT 'Final Size of ' + db_name() + ' LOG is ' + DB_oRr[oj
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 4gdXO
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ~|ZAS]
FROM sysfiles ,HmGp
WHERE name = @LogicalFileName _%B,^0;C
DROP TABLE DummyTrans 3DB= Xh
SET NOCOUNT OFF :eB+t`M
8、说明:更改某个表 AeN:wOm
exec sp_changeobjectowner 'tablename','dbo' Us2> 5 :\
9、存储更改全部表 ,1JQjsR
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch hb/Z{T'
@OldOwner as NVARCHAR(128), t7xJ"
@NewOwner as NVARCHAR(128) /d Ua
AS KbK!4
DECLARE @Name as NVARCHAR(128) <mTo54g
DECLARE @Owner as NVARCHAR(128) YN:Sn\`D 8
DECLARE @OwnerName as NVARCHAR(128) Zu4CFX-4
DECLARE curObject CURSOR FOR P6ka'!z
select 'Name' = name, ]~f-8!$$R
'Owner' = user_name(uid) o8%o68py
from sysobjects MTgf.
where user_name(uid)=@OldOwner [z=!OFdE
order by name US-f<Wq
OPEN curObject EGFPv'De
FETCH NEXT FROM curObject INTO @Name, @Owner x;~@T9.
WHILE(@@FETCH_STATUS=0) AE`{k-3=%
BEGIN Qm"~XP
if @Owner=@OldOwner ;:J"- p
begin NE)w$>0M
set @OwnerName = @OldOwner + '.' + rtrim(@Name) d/$e#8
exec sp_changeobjectowner @OwnerName, @NewOwner sE|8a
end `022gHYv
-- select @name,@NewOwner,@OldOwner _,UYbD\[J}
FETCH NEXT FROM curObject INTO @Name, @Owner 6U%d3"T
END 1 <lfo^B
close curObject FB>P39u
deallocate curObject d.B<1"MQ
GO '}(Fj2P79
10、SQL SERVER中直接循环写入数据 m6xbO
declare @i int M\IdQY-c
set @i=1 oblw!)
while @i<30 l^}5PHLd
begin vMn$lT@
insert into test (userid) values(@i) SNSoV3|k-
set @i=@i+1 00y(E@~
end `w@z
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小记存储过程中经常用到的本周,本月,本年函数 5bI4'
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Dateadd(wk,datediff(wk,0,getdate()),-1) 4 EA$<n(A-
Dateadd(wk,datediff(wk,0,getdate()),6) "@5{=
Dateadd(mm,datediff(mm,0,getdate()),0) `Jj b4]
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) v{*2F
Dateadd(yy,datediff(yy,0,getdate()),0) }v_|N"@
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 8(S|=c R
上面的SQL代码只是一个时间段 0%IZ -])
Dateadd(wk,datediff(wk,0,getdate()),-1) 4Sdj#w
Dateadd(wk,datediff(wk,0,getdate()),6) pjSM7PhQ
就是表示本周时间段. $ >].;y?$
下面的SQL的条件部分,就是查询时间段在本周范围内的: QAZs1;lU
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ]2iIk=r$
而在存储过程中 Y( K`3?A
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 55y{9.n*
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) %.\+j,G7