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。 q`1"]gy.
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一、基础 L?_'OwaY
1、说明:创建数据库 z,pKyInw
CREATE DATABASE database-name = F*SAz
2、说明:删除数据库
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drop database dbname }LK +w+h~
3、说明:备份sql server g=*'kj7c3
--- 创建 备份数据的 device .SZ ZT0Z
USE master E,u/^V9x
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' H_w&_h&
--- 开始 备份 /-%0y2"7
BACKUP DATABASE pubs TO testBack D d['e
4、说明:创建新表 $gZC"~BR
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) qiEw[3Za]'
根据已有的表创建新表: I'6wh+
A:create table tab_new like tab_old (使用旧表创建新表) Z:>)5Z{'
B:create table tab_new as select col1,col2... from tab_old definition only t}FwS6u
5、说明:删除新表 =PU!hZj"L
drop table tabname `sW+R=
6、说明:增加一个列 P/%5J3_,
Alter table tabname add column col type yN-o?[o
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。 X5[.X()M4
7、说明:添加主键: Alter table tabname add primary key(col) v\&C]W]
说明:删除主键: Alter table tabname drop primary key(col) "[A]tklP
8、说明:创建索引:create [unique] index idxname on tabname(col....) ^j~CYzmt
删除索引:drop index idxname =CBY_
注:索引是不可更改的,想更改必须删除重新建。 MZJ@qIg[Y
9、说明:创建视图:create view viewname as select statement v_U+wga
删除视图:drop view viewname i'bviD
10、说明:几个简单的基本的sql语句 'uy\vR&Pz
选择:select * from table1 where 范围 ?2d! ^!9
插入:insert into table1(field1,field2) values(value1,value2) Z`jc*jgy
删除:delete from table1 where 范围 $2!|e,x
更新:update table1 set field1=value1 where 范围 ;t6)(d4z?
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! }EJAC*W,
排序:select * from table1 order by field1,field2 [desc] s=KK)6T
总数:select count as totalcount from table1 O4`am:@
求和:select sum(field1) as sumvalue from table1 3m;*gOLk6
平均:select avg(field1) as avgvalue from table1 ?7;_3+T#
最大:select max(field1) as maxvalue from table1 0eJqDCmH
最小:select min(field1) as minvalue from table1 "~V|p3
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11、说明:几个高级查询运算词 J}zN]|bz
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A: UNION 运算符 }N^3P0XjYq
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。 76IjM4&a
B: EXCEPT 运算符 C!,|Wi2&
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。 )By#({O
C: INTERSECT 运算符 M\m6|P
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。 ,a6Oi=+>/U
注:使用运算词的几个查询结果行必须是一致的。 b=87k
12、说明:使用外连接 9nGS"E l{
A、left outer join: PiL[&_8g
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。 Hl|EySno
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 -F->l5
B:right outer join: cc0e(\
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。 GkU]>8E'"
C:full outer join: :o37 V!
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。 +cXdF
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二、提升 1r:i'cWh
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) P<E!ix
法一:select * into b from a where 1<>1 =|j~*6Hd
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) 7my7|s[
insert into b(a, b, c) select d,e,f from b; Ung K9uB~
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) ~;AJB
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 v)c[-:"z
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. ]ykMh
4、说明:子查询(表名1:a 表名2:b) =w,cdU*
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) KtMD?
5、说明:显示文章、提交人和最后回复时间 V#Pz`D
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b (_ TKDx_
6、说明:外连接查询(表名1:a 表名2:b) qA;!Pql`
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c y+aL5$x6
7、说明:在线视图查询(表名1:a ) UL3++bt
select * from (SELECT a,b,c FROM a) T where t.a > 1; c{(4s6D
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 Bk
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select * from table1 where time between time1 and time2 KlbUs\E
select a,b,c, from table1 where a not between 数值1 and 数值2 _N1UL?
9、说明:in 的使用方法 P`$Y73L
select * from table1 where a [not] in ('值1','值2','值4','值6') [kp#
10、说明:两张关联表,删除主表中已经在副表中没有的信息 Yn>y1~
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) b0:5i<"w6
11、说明:四表联查问题: {G i:W/jJ
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... E|9'{3$
12、说明:日程安排提前五分钟提醒 w8KVs\/
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 K0 6 E:
13、说明:一条sql 语句搞定数据库分页 BpR#3CfW
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 )4O* D92
14、说明:前10条记录 <#ZDA/G(
select top 10 * form table1 where 范围 A5q%ytI
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.) C<B1zgX
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) |M$ESj4@
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 \L]T|]}(
(select a from tableA ) except (select a from tableB) except (select a from tableC) y%Wbm&h
17、说明:随机取出10条数据
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select top 10 * from tablename order by newid() #U?=D/
18、说明:随机选择记录 nq,P.~l
select newid() d>bS)
19、说明:删除重复记录 wM0P#+bA\
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) z$]HZ#aRE
20、说明:列出数据库里所有的表名 p6*|)}T_%
select name from sysobjects where type='U' Kc#42C;t/
21、说明:列出表里的所有的 IzWS6!zKU
select name from syscolumns where id=object_id('TableName') oc0z1u
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。 LVAnZ'h/|
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 iJ%`ym4Y
显示结果: hcrx(oJ5
type vender pcs w=}R'O;k
电脑 A 1 PvkHlb^x%
电脑 A 1 4+2hj*I
光盘 B 2 Z5[f
光盘 A 2 wf&1,t3Bgn
手机 B 3
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手机 C 3 fs3jPHZJ#
23、说明:初始化表table1 }DzN-g<K
TRUNCATE TABLE table1 1 GB
24、说明:选择从10到15的记录 \EC7*a0
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ;sZHE&+
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三、技巧 ?]Z EK8c
1、1=1,1=2的使用,在SQL语句组合时用的较多 ?cmv;KV
"where 1=1" 是表示选择全部 "where 1=2"全部不选, F qH@iZ
如: K4|{[YpPB
if @strWhere !='' I/Q5Y- atg
begin ]>"q>XgnI
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere KX $Q`lM
end 'X]my
else 2I
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begin <CM}g4Y
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' w@Gk#
end :d`8:gv?
我们可以直接写成 6H:'_|G
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere Xw<5VIAHm;
2、收缩数据库 3^%sz!jK+
--重建索引 H>Ws)aCq
DBCC REINDEX ]>'yt #]
DBCC INDEXDEFRAG 3!<} -sW4
--收缩数据和日志 B_uAa5'
DBCC SHRINKDB EC0M0qQ
DBCC SHRINKFILE u4,b%h.
3、压缩数据库 @"$rR+r'
dbcc shrinkdatabase(dbname) Ymr\8CG/
4、转移数据库给新用户以已存在用户权限 >x6$F*:W}
exec sp_change_users_login 'update_one','newname','oldname' K" U!SWv
go a8[Q1Fa4|
5、检查备份集 g$eZT{{W
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Z+J;nl
6、修复数据库 ?&>H^}gDZ
ALTER DATABASE [dvbbs] SET SINGLE_USER }y P98N5o
GO /{7we$+,p
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK AYLCdCoK.
GO
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ALTER DATABASE [dvbbs] SET MULTI_USER K-f\nr
GO cQ<* (KU
7、日志清除 VN[i;4o:|
SET NOCOUNT ON \y*,N^w u
DECLARE @LogicalFileName sysname, ukH?O)0O
@MaxMinutes INT, *iW$>Yjb
@NewSize INT M!E#T-)
USE tablename -- 要操作的数据库名 |Je+y;P7
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 M_monj}Z
@MaxMinutes = 10, -- Limit on time allowed to wrap log. eOI#T'5
@NewSize = 1 -- 你想设定的日志文件的大小(M) cojbuo
-- Setup / initialize 8OW504AD
DECLARE @OriginalSize int h1uD >heGl
SELECT @OriginalSize = size c$w} h[
FROM sysfiles q7'[II;
WHERE name = @LogicalFileName 0Fi&7%
SELECT 'Original Size of ' + db_name() + ' LOG is ' + D_MNF=7
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + O&c~7tM%
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' $xsmF?Dsx5
FROM sysfiles QW_QizR>|
WHERE name = @LogicalFileName *E- VS= #
CREATE TABLE DummyTrans K`d3p{M
(DummyColumn char (8000) not null) g
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DECLARE @Counter INT, ]p.eF YDh7
@StartTime DATETIME, T1}9^3T?{
@TruncLog VARCHAR(255) `'^&*
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SELECT @StartTime = GETDATE(), /|.
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' _Mis-K:]{?
DBCC SHRINKFILE (@LogicalFileName, @NewSize) B hnwb0b<
EXEC (@TruncLog) NXyuv7%5=
-- Wrap the log if necessary. te b~KM
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ~jqh&u$(
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) =*u:@T=d5
AND (@OriginalSize * 8 /1024) > @NewSize Gr
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BEGIN -- Outer loop. VSI.c`=,
SELECT @Counter = 0 3M&IMf,/@
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) <(%cb.^c=N
BEGIN -- update ErDt~FH
INSERT DummyTrans VALUES ('Fill Log') )5M9Ro7
DELETE DummyTrans /`Wd+
SELECT @Counter = @Counter + 1 Hx]{'?
END G$buZspL'd
EXEC (@TruncLog) 389puDjy
END s`$px2Gw
SELECT 'Final Size of ' + db_name() + ' LOG is ' + vs)1Rm
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + @Fl&@ $
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' cKj6tT"=O
FROM sysfiles [Bz'c1
WHERE name = @LogicalFileName uPtHCP6
DROP TABLE DummyTrans sa71Vh{
SET NOCOUNT OFF &2!F:L
8、说明:更改某个表 .7nr :P
exec sp_changeobjectowner 'tablename','dbo' W2a9P_
9、存储更改全部表 XU}sbbwu
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ]GS@ ub
@OldOwner as NVARCHAR(128), .2jG~_W[
@NewOwner as NVARCHAR(128) pSq3\#Twr
AS )n[ oP%
DECLARE @Name as NVARCHAR(128) GAlAFsB
DECLARE @Owner as NVARCHAR(128) N!e?K=}tL
DECLARE @OwnerName as NVARCHAR(128) Dl#%tYL+3h
DECLARE curObject CURSOR FOR Odo"S;)
select 'Name' = name, -;?5<>zZ
'Owner' = user_name(uid) w]{NaNIeq1
from sysobjects }0({c~z\
where user_name(uid)=@OldOwner ]bq<vI%
order by name gr/o!NC
OPEN curObject n+EK}=DK
FETCH NEXT FROM curObject INTO @Name, @Owner ?CQ\94kO
WHILE(@@FETCH_STATUS=0) E!4Qc+.
BEGIN Q1Jkt
if @Owner=@OldOwner :q2tda
begin cJ%u&2J_
set @OwnerName = @OldOwner + '.' + rtrim(@Name) .+H8c.
exec sp_changeobjectowner @OwnerName, @NewOwner ='7n
end USnKj_e
-- select @name,@NewOwner,@OldOwner .bm#|X)RO
FETCH NEXT FROM curObject INTO @Name, @Owner l_!.yV{
END A;sd rA
close curObject &B^vHH
deallocate curObject eqSCNYN
GO +McKyEa
10、SQL SERVER中直接循环写入数据 1D fB9n
declare @i int $FgpFxz;
set @i=1 U=C8gVb{Hq
while @i<30 "Q~6cH[#
begin |f^/((:D
insert into test (userid) values(@i) 27vLI~
set @i=@i+1 3mIX9&/
end sg(L`P
小记存储过程中经常用到的本周,本月,本年函数 H7e/6t<x
Dateadd(wk,datediff(wk,0,getdate()),-1) fuQ|[tpvQG
Dateadd(wk,datediff(wk,0,getdate()),6) eo4<RDe<
Dateadd(mm,datediff(mm,0,getdate()),0) gev7eGH<
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) yT42u|xZA
Dateadd(yy,datediff(yy,0,getdate()),0) ?wps_XU
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) $a6&OH/
上面的SQL代码只是一个时间段 vpY|S2w)Bp
Dateadd(wk,datediff(wk,0,getdate()),-1) :\*hAV1i
Dateadd(wk,datediff(wk,0,getdate()),6)
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就是表示本周时间段. ->-
下面的SQL的条件部分,就是查询时间段在本周范围内的: gFvFd:"uZ
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) j\nnx8`7
而在存储过程中 RGGP6SDc
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) &50Kn[
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) )S$!36Ni[