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。 *1v[kWa?
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一、基础 mS^tX i5hg
1、说明:创建数据库 KVT-P};jy*
CREATE DATABASE database-name ;\]b T;#
2、说明:删除数据库
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drop database dbname ?AJKBW^
3、说明:备份sql server @)|C/oA
--- 创建 备份数据的 device EB2w0a5
USE master 4)@mSSfn.
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' WU
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--- 开始 备份 BQ=PW|[
BACKUP DATABASE pubs TO testBack EdlTdn@A
4、说明:创建新表 n/Sw P
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 3QG7C{
根据已有的表创建新表: %kS(LlL+6
A:create table tab_new like tab_old (使用旧表创建新表) )(ImLbM)
B:create table tab_new as select col1,col2... from tab_old definition only Hea;?4Vg
5、说明:删除新表 | N[<x@
drop table tabname t5y;CxL
6、说明:增加一个列 NWMFtT
Alter table tabname add column col type [R=yF ~-
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。 iV&6nh(
7、说明:添加主键: Alter table tabname add primary key(col) x4E7X_
说明:删除主键: Alter table tabname drop primary key(col) ldiD2
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8、说明:创建索引:create [unique] index idxname on tabname(col....) Fs9I7~L3
删除索引:drop index idxname *=(lyx_O
注:索引是不可更改的,想更改必须删除重新建。 gDQ1?N'8{t
9、说明:创建视图:create view viewname as select statement 9y<*8bI
删除视图:drop view viewname 9~p[
10、说明:几个简单的基本的sql语句 L<ue$'
选择:select * from table1 where 范围 1][4.}?F[
插入:insert into table1(field1,field2) values(value1,value2) !HnXXVW
删除:delete from table1 where 范围 Tk5W'p|6f
更新:update table1 set field1=value1 where 范围 _F$aUtb%O
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 5]AC*2(
排序:select * from table1 order by field1,field2 [desc] #vti+A~n,4
总数:select count as totalcount from table1 %= fHu+
求和:select sum(field1) as sumvalue from table1 yXHUJgjl/
平均:select avg(field1) as avgvalue from table1 KY51rw.
最大:select max(field1) as maxvalue from table1 [n \2
最小:select min(field1) as minvalue from table1 ]Q>.HH
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11、说明:几个高级查询运算词 +RyjF~[e
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A: UNION 运算符 z^#;~I @M
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。 KX'{[7}m'
B: EXCEPT 运算符 *7ZN]/VRT
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。 a1_GIM0
C: INTERSECT 运算符 AlAY iUw{
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}PhN<Gd
注:使用运算词的几个查询结果行必须是一致的。 i*/Yz*<
12、说明:使用外连接 D/vOs[X
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A、left outer join: NT e5
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。 5N/%v&1
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 D ,o}el
B:right outer join: 5hQE4/hH
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。 TFkZp e;
C:full outer join: A
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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。 (9Ux{@$o[
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二、提升 VQ7*Z5[1
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) B9NWW6S
法一:select * into b from a where 1<>1 19E8'@
法二:select top 0 * into b from a tt0f-:#
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) @zU6t|mhz
insert into b(a, b, c) select d,e,f from b; .J)I | '
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 6W]9$n\"?
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 G(p`1~xm
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. lT&eJO~?5
4、说明:子查询(表名1:a 表名2:b) uRZ ZxZ
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) _kU:Z
5、说明:显示文章、提交人和最后回复时间 o<COm9)i
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b =kJ,%\E`
6、说明:外连接查询(表名1:a 表名2:b) y5?RVlKJ
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Ji>o!
7、说明:在线视图查询(表名1:a ) n%-R[vW
select * from (SELECT a,b,c FROM a) T where t.a > 1; `(_s|-$
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 * +"9%&?
select * from table1 where time between time1 and time2 2jR r,Nl
select a,b,c, from table1 where a not between 数值1 and 数值2 /OLFcxEWh
9、说明:in 的使用方法 >8WP0Qx/
select * from table1 where a [not] in ('值1','值2','值4','值6') ]:4*L
10、说明:两张关联表,删除主表中已经在副表中没有的信息 Ju96#v+:
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 2+QY hdw
11、说明:四表联查问题: i rU 6D
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 ..... Y
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12、说明:日程安排提前五分钟提醒 ow_W%I=6
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 {2=jAz'?
13、说明:一条sql 语句搞定数据库分页 Y2n!>[[.
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 BK)$'AqO
14、说明:前10条记录 g;qx">xJ`o
select top 10 * form table1 where 范围 DW5Y@;[
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) [|(N_[E|6
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) YKH\rN6X
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 8Kg n"M3
(select a from tableA ) except (select a from tableB) except (select a from tableC) x[h^[oF0
17、说明:随机取出10条数据 8ZM&(Lz7u
select top 10 * from tablename order by newid() *K|W
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18、说明:随机选择记录 pA9+Cr!0Q
select newid() &7PG.Ff!r
19、说明:删除重复记录 nExU#/*~^
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) wO'TBP
20、说明:列出数据库里所有的表名 YG@t5j#b
select name from sysobjects where type='U' w<Wf?a G
21、说明:列出表里的所有的 =t9\^RIx)?
select name from syscolumns where id=object_id('TableName') Cs9.&Y
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 8u6:=fxb
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type VH9dleZ
显示结果: /{+y2.{j
type vender pcs mRL"nC
电脑 A 1 "D63I|O)
电脑 A 1 +jS|2d
光盘 B 2 /67 h&j
光盘 A 2 g.BdlVB\
手机 B 3 q"\Z-D0B4
手机 C 3 7gj4j^a^]{
23、说明:初始化表table1 AgS7J(^&3
TRUNCATE TABLE table1 wQ^EYKD
24、说明:选择从10到15的记录 -:|?h{q?u
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Al}6q{E9+8
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三、技巧 Fq|Ni$
1、1=1,1=2的使用,在SQL语句组合时用的较多 z\K"Rg~J
"where 1=1" 是表示选择全部 "where 1=2"全部不选, yE:+Lo`>
如: ;j[>9g
if @strWhere !='' h"X;3b^ m
begin &,zq%;-f
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere |bTPtrT8
end G`cHCP_n
else ZrPbl"`7
begin KN<S}3MN
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' n^Hm;BiE#
end NQBpX
我们可以直接写成 s}w{:Hk,x8
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere h2Ld[xvCu%
2、收缩数据库 )J2mM
--重建索引 vdAr|4^qB
DBCC REINDEX #|L8tuWW
DBCC INDEXDEFRAG +R3k-' >
--收缩数据和日志 39:bzUIF
DBCC SHRINKDB ?9e_gV{&;
DBCC SHRINKFILE O_`VV*
3、压缩数据库
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dbcc shrinkdatabase(dbname) ^E;kgED5
4、转移数据库给新用户以已存在用户权限 U#lCj0iUt,
exec sp_change_users_login 'update_one','newname','oldname' A P)L:7w'e
go Bt@^+vH ~
5、检查备份集 Q# ~Q=T'<
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' _K]_
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6、修复数据库 EMY/~bQW
ALTER DATABASE [dvbbs] SET SINGLE_USER idLWe9gC
GO .nrMfl_
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK q]T1dz?
GO z[b@V
ALTER DATABASE [dvbbs] SET MULTI_USER iW$_zgN
GO d' !]ZWe
7、日志清除 RIlwdt
SET NOCOUNT ON ]~9tYn
DECLARE @LogicalFileName sysname, ZGexdc%
@MaxMinutes INT, wxKX{Bs
@NewSize INT ?qPo=~y01
USE tablename -- 要操作的数据库名 SheM|I~de
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 .B7,j%1r
@MaxMinutes = 10, -- Limit on time allowed to wrap log. \H1(PA
@NewSize = 1 -- 你想设定的日志文件的大小(M) u_@f$
-- Setup / initialize !hJ+Lp_
DECLARE @OriginalSize int 5eLtCsHz
SELECT @OriginalSize = size q
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FROM sysfiles |cK*~
WHERE name = @LogicalFileName vx>b^tJKC
SELECT 'Original Size of ' + db_name() + ' LOG is ' + `7c~mypx
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + %Qmn-uZ
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ;D3C>7y
FROM sysfiles e|)hG8FlF
WHERE name = @LogicalFileName CyJEY-
CREATE TABLE DummyTrans NP0\i1P>.?
(DummyColumn char (8000) not null) T$>WE= Y
DECLARE @Counter INT, 9]k @Q_
@StartTime DATETIME, ( /=f6^}
@TruncLog VARCHAR(255) MLXN Zd
SELECT @StartTime = GETDATE(), GZEc l'h*
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ?4+9fE<Q
DBCC SHRINKFILE (@LogicalFileName, @NewSize) VLOO8N[o
EXEC (@TruncLog) zwhe
-- Wrap the log if necessary. Luq#9(P
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Ur9?Td'*>
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) D9<!mH
AND (@OriginalSize * 8 /1024) > @NewSize N4v~;;@(
BEGIN -- Outer loop. NSxoF3
SELECT @Counter = 0 ?^7t'`zk
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 2<i!{;u$qL
BEGIN -- update $Ipg&`S"
INSERT DummyTrans VALUES ('Fill Log') Njxv4cc
DELETE DummyTrans Z_$%.
SELECT @Counter = @Counter + 1 C^O
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END =O&%c%~q
EXEC (@TruncLog) $mu^G t
END *1uKr9
SELECT 'Final Size of ' + db_name() + ' LOG is ' + o*-)Tq8GHE
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + U_M$#i{_
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' '}9x\3E
FROM sysfiles hpHr\g
WHERE name = @LogicalFileName #*D)Q/k
DROP TABLE DummyTrans |t^E~HLm,
SET NOCOUNT OFF .k#U]M
8、说明:更改某个表 >=qf/K+#
exec sp_changeobjectowner 'tablename','dbo' @Pm>sY}d<I
9、存储更改全部表 O8+7g+J=!
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch r/YMLQ
@OldOwner as NVARCHAR(128), (SWYOMo"
@NewOwner as NVARCHAR(128) x6Bu F_.
AS YJ^]
u}
DECLARE @Name as NVARCHAR(128) bn#"?6Z2
DECLARE @Owner as NVARCHAR(128) Bn^0^J-
DECLARE @OwnerName as NVARCHAR(128) TITKj?*o
DECLARE curObject CURSOR FOR L9r8BK;
select 'Name' = name, J*r*X.
'Owner' = user_name(uid) -f3p U:G8
from sysobjects ?iw!OoZ`
where user_name(uid)=@OldOwner P0SQr?W
order by name \MA+f~)9
OPEN curObject ^UciW
FETCH NEXT FROM curObject INTO @Name, @Owner C;;Sih5
WHILE(@@FETCH_STATUS=0) c?tBi9'Y]
BEGIN q_Q/3rh
if @Owner=@OldOwner y0Fb_"}
begin &:;:"{t}Do
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ~FZ&.<s
exec sp_changeobjectowner @OwnerName, @NewOwner xu>9(,l
end V_R@o3kv;
-- select @name,@NewOwner,@OldOwner xR-%L
FETCH NEXT FROM curObject INTO @Name, @Owner F0pir(n-
END hcgMZT!<5
close curObject 4-?C>
deallocate curObject zpzK>DH(
GO Cl5uS%g
10、SQL SERVER中直接循环写入数据 |WQBDB`W
declare @i int ]q;Emy
set @i=1 @fHi\W2JG
while @i<30 PxTwPl
begin u#Pa7_zBj]
insert into test (userid) values(@i) srr
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set @i=@i+1 |v`AA?@{8
end }K7#Q
小记存储过程中经常用到的本周,本月,本年函数 GD&uQ`Y5
Dateadd(wk,datediff(wk,0,getdate()),-1) .!Qki@
Dateadd(wk,datediff(wk,0,getdate()),6) (iBNZ7sJ
Dateadd(mm,datediff(mm,0,getdate()),0) aEFJ;n7m
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 68NYIyTW9
Dateadd(yy,datediff(yy,0,getdate()),0) ~d
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) Sj-n;F|=X
上面的SQL代码只是一个时间段 spGb!Y`mR
Dateadd(wk,datediff(wk,0,getdate()),-1) 5 f@)z"j
Dateadd(wk,datediff(wk,0,getdate()),6) ?L5zC+c!
就是表示本周时间段. pf2[,v/
下面的SQL的条件部分,就是查询时间段在本周范围内的: b[sx_b
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) XtXEB<4Z
而在存储过程中 8Ry3`ct
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) &x=.$76
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) F<ZYh