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。 ,!u@:UBT
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一、基础 e4%*I8
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1、说明:创建数据库 810<1NP
CREATE DATABASE database-name s
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2、说明:删除数据库 RTBBb:eX
drop database dbname T&"dBoUq>G
3、说明:备份sql server 0W%}z}/N
--- 创建 备份数据的 device E816YS='
USE master 3b\8907
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' ^WW|AS
--- 开始 备份 -<JBKPtA
BACKUP DATABASE pubs TO testBack B~g05`s
4、说明:创建新表 VN-#R=D
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ;Pqyu
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根据已有的表创建新表: &W<>^C2v
A:create table tab_new like tab_old (使用旧表创建新表) Yj7= T%5
B:create table tab_new as select col1,col2... from tab_old definition only /uXRZ
5、说明:删除新表 @))}\:
drop table tabname 8w8I:*
6、说明:增加一个列 skDk/-*R
Alter table tabname add column col type hi
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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。 '}pgUh_
7、说明:添加主键: Alter table tabname add primary key(col) }A)36
说明:删除主键: Alter table tabname drop primary key(col) !:O/|.+Vmf
8、说明:创建索引:create [unique] index idxname on tabname(col....) /.kna4k
删除索引:drop index idxname j YIV^o 0
注:索引是不可更改的,想更改必须删除重新建。 Sa?5iFg
9、说明:创建视图:create view viewname as select statement Lr?4Y
删除视图:drop view viewname n &\'Hm
10、说明:几个简单的基本的sql语句 { .3
选择:select * from table1 where 范围 P`3s\8[Q
插入:insert into table1(field1,field2) values(value1,value2) -Xxu/U})%
删除:delete from table1 where 范围 "^
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更新:update table1 set field1=value1 where 范围 ')u5 l
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ?%xhe
排序:select * from table1 order by field1,field2 [desc] gAr`hXO
总数:select count as totalcount from table1 `f6)Q`n
求和:select sum(field1) as sumvalue from table1 lO2T/1iMTW
平均:select avg(field1) as avgvalue from table1 TcKvSdr'
最大:select max(field1) as maxvalue from table1 l'7Mw%6{
最小:select min(field1) as minvalue from table1 1ntkM?
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11、说明:几个高级查询运算词 TXJY2J*24
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A: UNION 运算符 s!hI:$J.
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 ;naq-%'Sg
B: EXCEPT 运算符 Q$fRi[/L
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。 5w,Z 7I8
C: INTERSECT 运算符 Y%fVt|
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。 y^d[( c
注:使用运算词的几个查询结果行必须是一致的。 vcw>v={x
12、说明:使用外连接 !]rETP_
A、left outer join: Tf#2"(!
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。 *,W!FxJ
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 <}EV*`w4
B:right outer join: 3`fJzS% O
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。 crJ7pe9
C:full outer join: JQ"`9RNb
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。 $!|8g`Tm
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二、提升 (# 6<k
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) &c!j`86y*
法一:select * into b from a where 1<>1 $hjP}- oUX
法二:select top 0 * into b from a MX!u$ei
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ~!]&>n;=G
insert into b(a, b, c) select d,e,f from b; AV:Xg4UJv
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) d ~{jEg
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 t."g\;
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. HzRX$IKB3(
4、说明:子查询(表名1:a 表名2:b) .M9d*qp`S
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) I 1 b
5、说明:显示文章、提交人和最后回复时间 bA@
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b hrs#ZZ:E
6、说明:外连接查询(表名1:a 表名2:b) Gnbfy4Z
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c `Yx-~y5X
7、说明:在线视图查询(表名1:a ) mje<d"bW
select * from (SELECT a,b,c FROM a) T where t.a > 1; 0jxO |N2)
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 AbUDn\0$
select * from table1 where time between time1 and time2 DtzA$|Q}
select a,b,c, from table1 where a not between 数值1 and 数值2 u0m5JD0/
9、说明:in 的使用方法 j5L)N
select * from table1 where a [not] in ('值1','值2','值4','值6') :s'o~
10、说明:两张关联表,删除主表中已经在副表中没有的信息 L([E98fo
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) _W)`cr
11、说明:四表联查问题: ;i<$7MR.e
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... hi!L\yi
12、说明:日程安排提前五分钟提醒 bTZ>@~$
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 &qJPwO
13、说明:一条sql 语句搞定数据库分页 weNzYMf%
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 U'tE^W
14、说明:前10条记录 16"#i
select top 10 * form table1 where 范围 =%!e(N'p
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.) CY34X2F
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) i 3m3zXt
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 Q*]$)D3n
(select a from tableA ) except (select a from tableB) except (select a from tableC) ,Pn-ZF
17、说明:随机取出10条数据 l B1#
select top 10 * from tablename order by newid() Lp_$?MCD.
18、说明:随机选择记录 EQ4#fAM)
select newid() 25UYOK}!
19、说明:删除重复记录 6SE6AL<b
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) kr%2 w
20、说明:列出数据库里所有的表名 6yY.!HRkr
select name from sysobjects where type='U' )h#]iGVN}
21、说明:列出表里的所有的 vu=me?m?(
select name from syscolumns where id=object_id('TableName') C)NC&fV
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。 n5|l|#c$N
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 m9Ax\lf
显示结果: !<&m]K
type vender pcs oizT-8i@N
电脑 A 1 h;-a`@rO ;
电脑 A 1 ][,4,?T7
光盘 B 2 Z1M>-[j)
光盘 A 2 'l~6ErBSg
手机 B 3 MU'@2c
手机 C 3 ] /+D^6
23、说明:初始化表table1 ~3gru>qI&
TRUNCATE TABLE table1 Br}h/!NU/
24、说明:选择从10到15的记录 p~K9
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select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc SyO79e*t
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三、技巧 [*)Z!)
1、1=1,1=2的使用,在SQL语句组合时用的较多 5!Bktgk.
"where 1=1" 是表示选择全部 "where 1=2"全部不选, sc W'AJJq
如: h>alGLN>
if @strWhere !='' ,w{m3;]_%
begin {^5?)/<
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere H6&7\Wbk
end - hzjV|
else C9qJP^F
begin Y#FO5O%W
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' mf' ]O,
end X<]qU3k5
我们可以直接写成 B6]<G-
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere _n"Ae?TP
2、收缩数据库 2Vk\L~K
--重建索引 Ri#H.T<'
DBCC REINDEX u=r`t(Z1H
DBCC INDEXDEFRAG 99=s4*xzM
--收缩数据和日志 wvMW|
DBCC SHRINKDB w8iR|TV
DBCC SHRINKFILE 0:&ZnE}##
3、压缩数据库 Zj*\"Ol
dbcc shrinkdatabase(dbname) :!fG; )=
4、转移数据库给新用户以已存在用户权限 g>
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exec sp_change_users_login 'update_one','newname','oldname' >^$2f&z
go "&~
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5、检查备份集 p'n4)I2#
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ]XA4;7
6、修复数据库 \}_Yd8
ALTER DATABASE [dvbbs] SET SINGLE_USER K93p"nHN
GO 9}29&O
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK &v!WVa?
GO N]N4^A'
ALTER DATABASE [dvbbs] SET MULTI_USER cK`"lxO
GO |3hY6aty
7、日志清除 CO?Xt+1hR
SET NOCOUNT ON 7=XL!:P
DECLARE @LogicalFileName sysname, >dzsQ^Nj
@MaxMinutes INT, ILwn&[A0
@NewSize INT Pw0Ci
USE tablename -- 要操作的数据库名 Oco YV J
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 m~#%Q?_ %
@MaxMinutes = 10, -- Limit on time allowed to wrap log. <spZ! #o
@NewSize = 1 -- 你想设定的日志文件的大小(M) :-`7Q\c }
-- Setup / initialize fyWO
DECLARE @OriginalSize int <?Wti_ /M
SELECT @OriginalSize = size !0,Mp@ j/
FROM sysfiles m~hoE8C$
WHERE name = @LogicalFileName >q~l21dUi
SELECT 'Original Size of ' + db_name() + ' LOG is ' + sj?3M@l95W
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + .lgPFr6X
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 9#d+RT
FROM sysfiles RW$:9~
WHERE name = @LogicalFileName ;Xvp6.:
CREATE TABLE DummyTrans ,m<H-gwa
(DummyColumn char (8000) not null) X^9d/}uTa
DECLARE @Counter INT, JPn$FQD
@StartTime DATETIME, YW\0k5[
@TruncLog VARCHAR(255) 7Q w|!
SELECT @StartTime = GETDATE(), h].~# *
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' s@hRqGd:
DBCC SHRINKFILE (@LogicalFileName, @NewSize) jjM\. KL]
EXEC (@TruncLog) :!a2]-D}
-- Wrap the log if necessary. wCf~O'XLw
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired `+:.L>5([
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) :,b
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AND (@OriginalSize * 8 /1024) > @NewSize l1U=f]
BEGIN -- Outer loop. 0[?ny`Y
SELECT @Counter = 0 @H>@[+S#
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) I\~G|B
BEGIN -- update 0$+fkDf
INSERT DummyTrans VALUES ('Fill Log') sVk$x:k1M
DELETE DummyTrans bwM@/g%DL
SELECT @Counter = @Counter + 1 h7*W*Bd
END m'\ 2:mDu0
EXEC (@TruncLog) rNjn~c
END h_1T,f(
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ZOXIT(mg
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + Ofm%:}LV
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' "<_0A f]
FROM sysfiles ~c)~015`
WHERE name = @LogicalFileName joKIrS0y
DROP TABLE DummyTrans Uj+j}C
SET NOCOUNT OFF ac kqH+'
8、说明:更改某个表 -[U1]R
exec sp_changeobjectowner 'tablename','dbo' y2]-&]&
9、存储更改全部表 D`J6h,=2l/
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch w.,Q1\*rPp
@OldOwner as NVARCHAR(128), )ZrS{vY
@NewOwner as NVARCHAR(128) 8Og_W8
AS / kt2c[9
DECLARE @Name as NVARCHAR(128) F":r4`5D"K
DECLARE @Owner as NVARCHAR(128) r]3'74j:
DECLARE @OwnerName as NVARCHAR(128) >5s6u`\
DECLARE curObject CURSOR FOR 5JEbe
select 'Name' = name, ebPgYxVZR
'Owner' = user_name(uid) p.+ho~sC,.
from sysobjects 2I*;A5$N1
where user_name(uid)=@OldOwner D]c`B
order by name N2.AKH
OPEN curObject Og=*R6i
FETCH NEXT FROM curObject INTO @Name, @Owner L?5Ck<!xG
WHILE(@@FETCH_STATUS=0) n,B,"\fw
BEGIN *@d&5
if @Owner=@OldOwner |t; ~:A
begin L\y;LSTU
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ynA|}X
exec sp_changeobjectowner @OwnerName, @NewOwner gTA%uRBa
end DjSbyXvrg
-- select @name,@NewOwner,@OldOwner b~nAPY6
FETCH NEXT FROM curObject INTO @Name, @Owner vjjSKP6B
END +}f9
close curObject 6N)!aT9eo
deallocate curObject <dW]\h?)
GO dt2$`X18
10、SQL SERVER中直接循环写入数据 !Hys3AP
declare @i int sP^R/z|Y
set @i=1 1"pw
while @i<30 kOh{l: 2-+
begin gi0W;q
insert into test (userid) values(@i) ChCrL[2
set @i=@i+1 f4L`.~b'hb
end 6oF7:lt
小记存储过程中经常用到的本周,本月,本年函数 < yC
Dateadd(wk,datediff(wk,0,getdate()),-1) D@!=d@V.
Dateadd(wk,datediff(wk,0,getdate()),6) v@e~k-#
Dateadd(mm,datediff(mm,0,getdate()),0) 765p/**
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) q$aaA`E%
Dateadd(yy,datediff(yy,0,getdate()),0) i\W/C
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) Qx [t/~
上面的SQL代码只是一个时间段 %;.;>Y(-
Dateadd(wk,datediff(wk,0,getdate()),-1) y#XbJuN/
Dateadd(wk,datediff(wk,0,getdate()),6) ;A#`]-i C
就是表示本周时间段. d>{nQF;c
下面的SQL的条件部分,就是查询时间段在本周范围内的: To?W?s
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6)
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而在存储过程中 o1<_fI
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) JGuN:c$
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) q7"7U=W0