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。 ^g*pGrl#
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一、基础 *Nw&_<\9Q
1、说明:创建数据库 /+8JCp
CREATE DATABASE database-name $iI]MV%=
2、说明:删除数据库 0n@rLF
drop database dbname #%`|~%`{:
3、说明:备份sql server un shH <
--- 创建 备份数据的 device FjK3
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USE master 0T@ Zb={
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' [r3 !\HI7x
--- 开始 备份 - d8TD*^
BACKUP DATABASE pubs TO testBack Q<z_/j9
4、说明:创建新表 ,%n\=
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) #?5 (o
根据已有的表创建新表: U3 */v4/
A:create table tab_new like tab_old (使用旧表创建新表) @*}D$}aR'V
B:create table tab_new as select col1,col2... from tab_old definition only qgE 73.!`6
5、说明:删除新表 wDcj,:h`
drop table tabname 4S,`bnmB
6、说明:增加一个列 ^cV;~&|.Xk
Alter table tabname add column col type [!!o-9b
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。 if}-_E<F
7、说明:添加主键: Alter table tabname add primary key(col) wkP#Z"A0~
说明:删除主键: Alter table tabname drop primary key(col)
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8、说明:创建索引:create [unique] index idxname on tabname(col....) I{
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删除索引:drop index idxname aki_RG>U'
注:索引是不可更改的,想更改必须删除重新建。 tDSJpW'd
9、说明:创建视图:create view viewname as select statement (]b!{kS
删除视图:drop view viewname =fu
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10、说明:几个简单的基本的sql语句 MA;1;uI,
选择:select * from table1 where 范围 U2{ dN>
插入:insert into table1(field1,field2) values(value1,value2) "Weg7mc#
删除:delete from table1 where 范围 +hvO^?4j
更新:update table1 set field1=value1 where 范围 `1'6bp`Z
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! &@%W29:
排序:select * from table1 order by field1,field2 [desc] UH]l9Aq$P
总数:select count as totalcount from table1 I3
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求和:select sum(field1) as sumvalue from table1 KQacoUHrK?
平均:select avg(field1) as avgvalue from table1 `n$I]_}/%
最大:select max(field1) as maxvalue from table1 :/y1yM
最小:select min(field1) as minvalue from table1 OTC!wI
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11、说明:几个高级查询运算词 MG[o%I96
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A: UNION 运算符 ${+ @gJ+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。 cU0s
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B: EXCEPT 运算符 S?RN?1
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。 cj+ FRG~u
C: INTERSECT 运算符 j]*j}%hz
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。 9&upujVS
注:使用运算词的几个查询结果行必须是一致的。 }-ftyl7
12、说明:使用外连接 KiI!frm1
A、left outer join: O?U'!o=
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。 )_{dWf1
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 ulu9'ch
B:right outer join: /E
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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。 XD |E=s
C:full outer join: x;-.
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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。 C3< m7h
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二、提升 9UKp?SIF
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) hc~s"Atck
法一:select * into b from a where 1<>1 D!.[q -<
法二:select top 0 * into b from a ()K " c#
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) "
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insert into b(a, b, c) select d,e,f from b; Y3r%B9~
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) 2rmSo&3@s
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 Yiry["[]Q
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. T_sTC)&a
4、说明:子查询(表名1:a 表名2:b) cs T2B[f9D
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) $rz=6h
5、说明:显示文章、提交人和最后回复时间 ':gUOra|I
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b GKvN*
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6、说明:外连接查询(表名1:a 表名2:b) qY~`8
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c =0^Ruh
7、说明:在线视图查询(表名1:a ) 1"/He ` 4
select * from (SELECT a,b,c FROM a) T where t.a > 1; yyv8gH
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 I*x[:)X8
select * from table1 where time between time1 and time2 Jj,U RD&0R
select a,b,c, from table1 where a not between 数值1 and 数值2 Gqcq,_?gt
9、说明:in 的使用方法 !,[C]Q1
select * from table1 where a [not] in ('值1','值2','值4','值6') qtiz a~u
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ?"zY"*>4
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) RQ'exc2x0
11、说明:四表联查问题: 0GB:GBhZ
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....
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12、说明:日程安排提前五分钟提醒 |AcRIq
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 fRy^Q_~,
13、说明:一条sql 语句搞定数据库分页 -:30:oq
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 e?_@aa9~@{
14、说明:前10条记录 70f Klp
select top 10 * form table1 where 范围 ]Tkc-ez
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) N-I5X2
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) JL\w_v
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 5m?8yT}
(select a from tableA ) except (select a from tableB) except (select a from tableC) 8'<-:KG
17、说明:随机取出10条数据 )t$,e2FY
select top 10 * from tablename order by newid() @fs`=lL/
18、说明:随机选择记录 |;.o8}
select newid() \"CZI<=TB
19、说明:删除重复记录 v-yde>(
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) }e2(T
20、说明:列出数据库里所有的表名 wNQ*t-K
select name from sysobjects where type='U' p3]_}Y
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21、说明:列出表里的所有的 :T]o)
select name from syscolumns where id=object_id('TableName') xEf'Bmebk
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。 VYt!U
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 0KMctPT]p
显示结果: mjWU0Gh%*
type vender pcs 2 Yp7
电脑 A 1 {]E+~%Va
电脑 A 1 f>piHh?
光盘 B 2 h3*Zfl<]
光盘 A 2 MF~H"D
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手机 B 3 (q{Ck#+
手机 C 3 ZKQG:M~|
23、说明:初始化表table1 @;<ht c
TRUNCATE TABLE table1 pY_s*0_
24、说明:选择从10到15的记录 _Qh
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select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc DA2}{
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三、技巧 3 n'V\Hvz
1、1=1,1=2的使用,在SQL语句组合时用的较多 SfJ./ny
"where 1=1" 是表示选择全部 "where 1=2"全部不选, }?z@rt^
如: 0Z0:,!
if @strWhere !='' n) k1
begin $aN-Y?U%
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere N@Y ljz|
end TF 'U
else <$ F\Nk|x
begin yY[<0|o u
set @strSQL = 'select count(*) as Total from [' + @tblName + ']'
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end taFn![}/!g
我们可以直接写成 87:!C5e}
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 5B&;uY
2、收缩数据库 C?i >.t
--重建索引 _~q?_'kx
DBCC REINDEX v^ zu:Z*
DBCC INDEXDEFRAG oP!;\a( SL
--收缩数据和日志 bYi`R)
DBCC SHRINKDB 2RN)<\ P
DBCC SHRINKFILE ]8T |f
3、压缩数据库 hQ(qbt{e
dbcc shrinkdatabase(dbname) :6zG7qES3
4、转移数据库给新用户以已存在用户权限 %{/%mJoX
exec sp_change_users_login 'update_one','newname','oldname' Eh =~T9
go NzU,va N
5、检查备份集 qf=1?=l291
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' /9zE^YcT
6、修复数据库 V5GW:QT
ALTER DATABASE [dvbbs] SET SINGLE_USER Tszp3,]f
GO 34wkzu
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK {dL?rQ>5L
GO MXzVgy
ALTER DATABASE [dvbbs] SET MULTI_USER [5uRS}!
GO $<^u^q37u
7、日志清除 "Kc>dJ@W
SET NOCOUNT ON wMdal:n^
DECLARE @LogicalFileName sysname, GrTulN?
@MaxMinutes INT, 6I!7c^]t
@NewSize INT :=8t"rO=W
USE tablename -- 要操作的数据库名 em\ 9'L^
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 KN?6;G{
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ;zYqsS
@NewSize = 1 -- 你想设定的日志文件的大小(M) a)S+8uU
-- Setup / initialize )13dn]o=2
DECLARE @OriginalSize int DK=cVpN%s
SELECT @OriginalSize = size B Ce|is0
FROM sysfiles y_HN6
WHERE name = @LogicalFileName T"&)&"W*U
SELECT 'Original Size of ' + db_name() + ' LOG is ' + Pfm_@'8
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ^Ve<>b
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' esHQoIhd
FROM sysfiles 0TmR/uUT
WHERE name = @LogicalFileName 0 H0-U'l
CREATE TABLE DummyTrans ^)?d6nI
(DummyColumn char (8000) not null) 63.wL0~
DECLARE @Counter INT, o$[z],RO
@StartTime DATETIME, !!4Qj
@TruncLog VARCHAR(255) V^hE}`>z&
SELECT @StartTime = GETDATE(), E[O<S B
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' n @?4b8"
DBCC SHRINKFILE (@LogicalFileName, @NewSize) _:X|.W
EXEC (@TruncLog) t9Y=m6
-- Wrap the log if necessary. cwm_nQKk
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Vpr/
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) z81esXl
AND (@OriginalSize * 8 /1024) > @NewSize *1 G>YH
BEGIN -- Outer loop. p_UlK8rb
SELECT @Counter = 0 @&]#uRl|[
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) m85WA
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BEGIN -- update ?x+Z)`w_
INSERT DummyTrans VALUES ('Fill Log') O/.Uh`T`6
DELETE DummyTrans 6m VuyI
SELECT @Counter = @Counter + 1 t^[8RhD
END u5~Ns&o&N
EXEC (@TruncLog) xS7$%w['
END h.!}3\Y
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Gcb|W&
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + H*bs31i{
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' @q"m5
FROM sysfiles 25NTIzI@@
WHERE name = @LogicalFileName -F=v6N {
DROP TABLE DummyTrans @xeAc0.^
SET NOCOUNT OFF "Tm[t?FMbe
8、说明:更改某个表 ,^gyH
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exec sp_changeobjectowner 'tablename','dbo' +3a?`Z
9、存储更改全部表 PG8^.)]M
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch M\Gdn92pd
@OldOwner as NVARCHAR(128), y!5$/`AF
@NewOwner as NVARCHAR(128) (ewe"N+
AS kPQtQh]y%
DECLARE @Name as NVARCHAR(128) e5.h ?
DECLARE @Owner as NVARCHAR(128) K9vIm4::d$
DECLARE @OwnerName as NVARCHAR(128) _DrJVC~6@
DECLARE curObject CURSOR FOR =l.+,|ZH!
select 'Name' = name, ATy*^sc&"
'Owner' = user_name(uid) <BSc* 9Q
from sysobjects P_c,BlfGMH
where user_name(uid)=@OldOwner oW^*l#v
order by name 7},)]da>,'
OPEN curObject w=|GJ0
FETCH NEXT FROM curObject INTO @Name, @Owner *=fr8
WHILE(@@FETCH_STATUS=0) R/^u/~<
BEGIN `+t.!tv!
if @Owner=@OldOwner U|HB=BP
begin Y=`
set @OwnerName = @OldOwner + '.' + rtrim(@Name) h?-#9<A
exec sp_changeobjectowner @OwnerName, @NewOwner (;%|-{7e-
end nuo Pg3Nl
-- select @name,@NewOwner,@OldOwner ,+g&o^T
FETCH NEXT FROM curObject INTO @Name, @Owner f50L,4,
END $!5\E>y#
close curObject kNT}dv]<
deallocate curObject VyRsPg[(
GO VdP`a(Yd;
10、SQL SERVER中直接循环写入数据 i/b'4o=8
declare @i int XX1Il;1G#
set @i=1 l<Q>N|1#k%
while @i<30 |oub!fG4
begin rCS#{x
insert into test (userid) values(@i) ^m/14 MN|
set @i=@i+1 zE)~0v4
end Fb/XC:AD
小记存储过程中经常用到的本周,本月,本年函数 QI]Ih
Dateadd(wk,datediff(wk,0,getdate()),-1) tTN?r 8
Dateadd(wk,datediff(wk,0,getdate()),6) 'TTUN=y
Dateadd(mm,datediff(mm,0,getdate()),0) Z_gC&7+
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) k'$!(*]\b
Dateadd(yy,datediff(yy,0,getdate()),0) m%"uPv\
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) p#SY /KIw
上面的SQL代码只是一个时间段 U$H@ jJ*
Dateadd(wk,datediff(wk,0,getdate()),-1) #q3l!3\mW
Dateadd(wk,datediff(wk,0,getdate()),6) k z"3ZDR
就是表示本周时间段. *WE1;msr
下面的SQL的条件部分,就是查询时间段在本周范围内的: 3x~{QG5Gn
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 4t/&.
而在存储过程中 #{9G sD
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) |!q$_at
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6)
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