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。 e3pnk
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一、基础 AbG &9=Ks
1、说明:创建数据库 :fW.-^"VP
CREATE DATABASE database-name <k5`&X!+
2、说明:删除数据库 My],6va^
drop database dbname EO"6Dq(
3、说明:备份sql server V:8@)Hc=
--- 创建 备份数据的 device /D8EI
USE master g<a<{|
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' j^{b^!4~}
--- 开始 备份 L^x5&CCwk
BACKUP DATABASE pubs TO testBack FXxN>\76.
4、说明:创建新表 UtPwWB_YV
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) SlT7L||Ww
根据已有的表创建新表: S<9gyW
A:create table tab_new like tab_old (使用旧表创建新表) hWm0$v1p
B:create table tab_new as select col1,col2... from tab_old definition only $i -zMa
5、说明:删除新表 df yrn%^Ia
drop table tabname _}^u-fJ/~
6、说明:增加一个列 3jS7 uU
Alter table tabname add column col type $-e=tWkgv
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 ~9bv Wd1D
7、说明:添加主键: Alter table tabname add primary key(col) 2=O))^8
说明:删除主键: Alter table tabname drop primary key(col) +dJ&tuL:S
8、说明:创建索引:create [unique] index idxname on tabname(col....) \ JG
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删除索引:drop index idxname <ipWMZae0F
注:索引是不可更改的,想更改必须删除重新建。 q6Rw4
9、说明:创建视图:create view viewname as select statement d&?F#$> 7|
删除视图:drop view viewname \D ^7Z97
10、说明:几个简单的基本的sql语句 moe/cO5a9
选择:select * from table1 where 范围 N|o>%)R
插入:insert into table1(field1,field2) values(value1,value2) ;)P5#S!n-
删除:delete from table1 where 范围 "5y<G:$+~
更新:update table1 set field1=value1 where 范围 JC/d:.
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! !L/tLHk+
排序:select * from table1 order by field1,field2 [desc] w~p4S+k&
总数:select count as totalcount from table1 @??u})^EL
求和:select sum(field1) as sumvalue from table1 OFp#<o,p
平均:select avg(field1) as avgvalue from table1 \Me"'.F?
最大:select max(field1) as maxvalue from table1 lqauk)(A0
最小:select min(field1) as minvalue from table1 8'n#O>V@
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11、说明:几个高级查询运算词 *0lt$F$~b
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A: UNION 运算符 g4i #1V=
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 "7:u0p!
B: EXCEPT 运算符 KjC[q
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 ["<5?!bU
C: INTERSECT 运算符 @::lJDGVv
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 \6Xn]S
注:使用运算词的几个查询结果行必须是一致的。 M`(;>Kp7
12、说明:使用外连接 {rz>^
A、left outer join: raSF3b/0
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 @}ZGY^
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c [+_\z',u
B:right outer join: } mgVC
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 aE}=^%D
C:full outer join: \;iG{}(
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 ?~{rf:Y
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二、提升 y)IGTW o
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) Oxpo6G
法一:select * into b from a where 1<>1 58 kv#;j
法二:select top 0 * into b from a 2lF WW(
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) aD0Q 0C+
insert into b(a, b, c) select d,e,f from b; n&(3o6i'
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 0=2H9v
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 IcRM4Ib))Q
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Rz)v-Yu
4、说明:子查询(表名1:a 表名2:b) cl?<
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select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) =7#u+*Yr9
5、说明:显示文章、提交人和最后回复时间 W31LNysH!;
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b B$@1QG
6、说明:外连接查询(表名1:a 表名2:b) .v N)A
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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 uQO(?nCi
7、说明:在线视图查询(表名1:a ) uwmoM>I W^
select * from (SELECT a,b,c FROM a) T where t.a > 1; 6Q?BwD+>
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 :vw0r`
select * from table1 where time between time1 and time2 1<;\6sg
select a,b,c, from table1 where a not between 数值1 and 数值2 c]S+70!n
9、说明:in 的使用方法 U<K|jsFo
select * from table1 where a [not] in ('值1','值2','值4','值6') *Rz!i m|
10、说明:两张关联表,删除主表中已经在副表中没有的信息 d~w}NK[(
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) hkkF1
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11、说明:四表联查问题: \dC.%#
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 ..... 9zmD6G!}t
12、说明:日程安排提前五分钟提醒 <yis
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 2*N&q|ED
13、说明:一条sql 语句搞定数据库分页 ys:1Z\$P
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 4F}g(
14、说明:前10条记录 ?a*fy}A|
select top 10 * form table1 where 范围 zw}@nqp
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.) cb\jrbj6
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) F">Nrj-bs
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 0~Um^q*'3
(select a from tableA ) except (select a from tableB) except (select a from tableC) +oE7~64LL
17、说明:随机取出10条数据 -bv>iIC
select top 10 * from tablename order by newid() &19lk
18、说明:随机选择记录 LZgwIMd
select newid() SJso'6 g
19、说明:删除重复记录 K-N]h
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) A9NOeE
20、说明:列出数据库里所有的表名 MA~|y_V
select name from sysobjects where type='U' H(
21、说明:列出表里的所有的 x8\E~6`,
select name from syscolumns where id=object_id('TableName') d/"gq}NT
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。 R>Z,TQU
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 SD)5?{6<
显示结果: aS c#&{
type vender pcs A@9U;8k
电脑 A 1 6 ,7/8
电脑 A 1 rhlW
光盘 B 2 8<wtf]x
光盘 A 2 Z'7 c^c7_
手机 B 3 9O(i+fM
手机 C 3 g(ZeFOn
23、说明:初始化表table1 c#]'#+aH
TRUNCATE TABLE table1 2U-#0,ll]
24、说明:选择从10到15的记录 p.6$w:eV
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Y\ #.EVz
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三、技巧 ]>]#zu$=c
1、1=1,1=2的使用,在SQL语句组合时用的较多 @2x0V]AI
"where 1=1" 是表示选择全部 "where 1=2"全部不选, =NVZ$K OZ
如: fvAh?<Ul
if @strWhere !='' V+4k!
begin }qgqb
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere L8,H9T#e
end eO|^Lu]+
else jhjW*F<u
begin eXskwV+7
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' clPZd
end @m !9"QhC
我们可以直接写成 @&nx;K6h
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ^.pE`l%1}
2、收缩数据库 m'G?0^Ft
--重建索引 N7RG5?
DBCC REINDEX 8GF[)z&|P:
DBCC INDEXDEFRAG g]EQ2g_N1
--收缩数据和日志 6xDl=*&%
DBCC SHRINKDB EOd.Tyb!/
DBCC SHRINKFILE ~:P8g<w
3、压缩数据库 Pj1K
dbcc shrinkdatabase(dbname) =]5DYRhX]
4、转移数据库给新用户以已存在用户权限 !`O_VV`/@
exec sp_change_users_login 'update_one','newname','oldname' 1 $KLMW
go E.7AbHph0
5、检查备份集 e)ZyTuj
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' } kh/mq
6、修复数据库 +O.&64(
ALTER DATABASE [dvbbs] SET SINGLE_USER Egjk^:@
GO iOX4Kl
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 886 ('
GO {WM&
ALTER DATABASE [dvbbs] SET MULTI_USER 3isXgp8
GO wB1-|=K1
7、日志清除 Pq[0vZ_}dN
SET NOCOUNT ON NIWI6qCw
DECLARE @LogicalFileName sysname, ]ut-wqb{p
@MaxMinutes INT, i5>J
@NewSize INT E7Gi6w~\
USE tablename -- 要操作的数据库名 %>I?'y^
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 c'TiWZP~
@MaxMinutes = 10, -- Limit on time allowed to wrap log. Y*5@|Q
@NewSize = 1 -- 你想设定的日志文件的大小(M) M&}oat*
-- Setup / initialize _!$Up
DECLARE @OriginalSize int Z;"4$@|qE
SELECT @OriginalSize = size ^w&5@3d
FROM sysfiles Pi"tQyw39$
WHERE name = @LogicalFileName \@
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SELECT 'Original Size of ' + db_name() + ' LOG is ' + NbQMWU~7
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + rH2tC=%
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' x[.z"$T@
FROM sysfiles gN!E*@7
WHERE name = @LogicalFileName + hyWo]nW0
CREATE TABLE DummyTrans yp^[]Mz=
(DummyColumn char (8000) not null) 2RSHBo
DECLARE @Counter INT, 1"4nmw}
@StartTime DATETIME, ga2Q3mV
@TruncLog VARCHAR(255) ()3x%3
SELECT @StartTime = GETDATE(), &"r==A?
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' xi1N?
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) -!bLMLIg
EXEC (@TruncLog) +qSr=Y:+
-- Wrap the log if necessary. ~Hyyq-
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Ck/_UY|
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) D<D
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AND (@OriginalSize * 8 /1024) > @NewSize M|Lw`?T
BEGIN -- Outer loop. _A~~L6C
SELECT @Counter = 0 v,!Y=8~9
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) s:m<(8WRw
BEGIN -- update :}3qZX
INSERT DummyTrans VALUES ('Fill Log') iuU3*yyn
DELETE DummyTrans :UJUh/U
SELECT @Counter = @Counter + 1 /F8\%l+
END xJF6l!`
EXEC (@TruncLog) W:+2We @
END 0imqj7L
SELECT 'Final Size of ' + db_name() + ' LOG is ' + _'v }=:X
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + G|6 |;
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'
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FROM sysfiles H>X>5_{}
WHERE name = @LogicalFileName "6*Kgf2G
DROP TABLE DummyTrans qqom$H<
SET NOCOUNT OFF "ZJ1`R=Mj
8、说明:更改某个表 ttAVB{kdo
exec sp_changeobjectowner 'tablename','dbo' hiK[!9r
9、存储更改全部表 G(|(y=ck
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch EkB6- nz
@OldOwner as NVARCHAR(128), !ovZ>,1
@NewOwner as NVARCHAR(128) !EmR (x
AS \dxW44sM
DECLARE @Name as NVARCHAR(128) ]RrP !|^
DECLARE @Owner as NVARCHAR(128) _G}CD|Kx
DECLARE @OwnerName as NVARCHAR(128) 5(MZ%-~l
DECLARE curObject CURSOR FOR \Q?|gfJH
select 'Name' = name, M\.T 0M_
'Owner' = user_name(uid) [nPzhXs
from sysobjects h7W%}6Cqkw
where user_name(uid)=@OldOwner f'i8Mm4IL
order by name ]stLC; nI
OPEN curObject g`5`KU|
FETCH NEXT FROM curObject INTO @Name, @Owner Uc4L|:
WHILE(@@FETCH_STATUS=0) +VpE-X=T
BEGIN @IyH(J],h
if @Owner=@OldOwner {, *Y
begin 4k&O-70y4^
set @OwnerName = @OldOwner + '.' + rtrim(@Name) XdIVMXLL\
exec sp_changeobjectowner @OwnerName, @NewOwner 3W0E6H"
end { d2f)ra.
-- select @name,@NewOwner,@OldOwner |>o0d~s
FETCH NEXT FROM curObject INTO @Name, @Owner 6L6~IXL>
END -JQg ~1
close curObject <sWcS; x
deallocate curObject @tv];t
GO 8hdAXWPn
10、SQL SERVER中直接循环写入数据 {@K2WB
declare @i int xMfv&q=k@
set @i=1 b=QGbFf
while @i<30 6`5
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begin #ZnX6=;X
insert into test (userid) values(@i) `Py=
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set @i=@i+1 3_eml\CY
end ?o(X0
小记存储过程中经常用到的本周,本月,本年函数 Xx<&6
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Dateadd(wk,datediff(wk,0,getdate()),-1) uA/.4 b
Dateadd(wk,datediff(wk,0,getdate()),6) *ZSp9g"Z
Dateadd(mm,datediff(mm,0,getdate()),0) 7%"\DLA
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) uSQ>oi]
Dateadd(yy,datediff(yy,0,getdate()),0) \F+o=
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) >La L!PnZ
上面的SQL代码只是一个时间段 3ws(uF9$
Dateadd(wk,datediff(wk,0,getdate()),-1) wyA(}iSq
Dateadd(wk,datediff(wk,0,getdate()),6) ~G^}2#5
就是表示本周时间段. 53+rpU_
下面的SQL的条件部分,就是查询时间段在本周范围内的: d_7Xlp@
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) VU0tyj$
而在存储过程中 .]ZuG
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) lbuW*)
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) =UKR<@QrK