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。 0`)iIz
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一、基础 U7doU' V/
1、说明:创建数据库 i:rFQ8I
CREATE DATABASE database-name 90|7ArM_[
2、说明:删除数据库 6lkl7zm
drop database dbname !_+8A/
3、说明:备份sql server N>Eqj>G
--- 创建 备份数据的 device <c)+Fno[E_
USE master :@1eph0
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' -od!J\KCy
--- 开始 备份 fbWFLSm;
BACKUP DATABASE pubs TO testBack
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4、说明:创建新表 c~{9a_G
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) {~h*2n
根据已有的表创建新表: .,7JAkB%t
A:create table tab_new like tab_old (使用旧表创建新表) W?0 lV5/
B:create table tab_new as select col1,col2... from tab_old definition only YoN*:jB<M
5、说明:删除新表 bV edFm
drop table tabname P~s$EJL*
6、说明:增加一个列 D'L'#/hK
Alter table tabname add column col type !O.[PH(,*
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。 -RO7
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7、说明:添加主键: Alter table tabname add primary key(col) r|PFw6
说明:删除主键: Alter table tabname drop primary key(col) /&CmO>^e
8、说明:创建索引:create [unique] index idxname on tabname(col....) d)@<W1;
删除索引:drop index idxname G P:FSprP
注:索引是不可更改的,想更改必须删除重新建。 ?."&MZ
9、说明:创建视图:create view viewname as select statement B=>RH!&
删除视图:drop view viewname Q:|l`*.R
10、说明:几个简单的基本的sql语句 K=C!b?
选择:select * from table1 where 范围 GwG4LIp
插入:insert into table1(field1,field2) values(value1,value2) '"?C4mbSl
删除:delete from table1 where 范围 '"<6.,Ae
更新:update table1 set field1=value1 where 范围 !(n4|Wd
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! V[}4L|ad
排序:select * from table1 order by field1,field2 [desc] Mva3+T
总数:select count as totalcount from table1 O(tX8P
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求和:select sum(field1) as sumvalue from table1 W%.v.0
平均:select avg(field1) as avgvalue from table1 L KCb_9
最大:select max(field1) as maxvalue from table1 |,#t^'S!
最小:select min(field1) as minvalue from table1 rsF\JQk
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11、说明:几个高级查询运算词 Y4cYZS47
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A: UNION 运算符 rC.eyq,105
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。 <V7>?U l
B: EXCEPT 运算符 VA"*6F
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。 r'dr9"-{
C: INTERSECT 运算符 R*oXmuOsYA
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。 `%E8-]{uS
注:使用运算词的几个查询结果行必须是一致的。 cooUE<a
12、说明:使用外连接 6\u!E~zy
A、left outer join: h)6GaJ=
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。 *\wp?s>-t
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 ZxG}ViS4I
B:right outer join: '8fk+>M
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。 $`8Ar,Xz`
C:full outer join: 7}GK%H-u
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 /^$UhX9v
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二、提升 "F3]X)}
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) HxBm~Lcqy
法一:select * into b from a where 1<>1 mCs#.%dU
法二:select top 0 * into b from a &X|<@'933
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) RbGJ)K!
insert into b(a, b, c) select d,e,f from b; 9prU+9
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) SFb{o<0 =
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 rUlS'L;$"
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Cv>o.Bp|
4、说明:子查询(表名1:a 表名2:b) mAeuw7Ni
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) .fi/I
5、说明:显示文章、提交人和最后回复时间 4<lQwV6=
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b BaO1/zk
6、说明:外连接查询(表名1:a 表名2:b) Tzt ,/e
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c zOHypazOTq
7、说明:在线视图查询(表名1:a ) kWlAY%
select * from (SELECT a,b,c FROM a) T where t.a > 1; /Y&02L%\3s
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 p1D[YeF4
select * from table1 where time between time1 and time2 cO\-
select a,b,c, from table1 where a not between 数值1 and 数值2 t ?h kL
9、说明:in 的使用方法 FVB;\'/
select * from table1 where a [not] in ('值1','值2','值4','值6') \eGKkSy
10、说明:两张关联表,删除主表中已经在副表中没有的信息 @)>D))+
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) P_gYz!
11、说明:四表联查问题: zf.-I
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... }C
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12、说明:日程安排提前五分钟提醒 :^'O}2NP
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 b$Hz3TJ(
13、说明:一条sql 语句搞定数据库分页 ZkP{[^6d\
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 >#}2J[2HQ
14、说明:前10条记录 !j1[$% =#
select top 10 * form table1 where 范围 ygSL
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) M wab!Ya
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) `e]6#iJ^
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 7l."b$U4yv
(select a from tableA ) except (select a from tableB) except (select a from tableC) !ph" mf$-
17、说明:随机取出10条数据 (>=7ng^
select top 10 * from tablename order by newid() 2/36dGFH
18、说明:随机选择记录 E15vq6 DKF
select newid() iB1i/l
19、说明:删除重复记录 RGIoI]_
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) BPqGJ7@
20、说明:列出数据库里所有的表名 j J3zF3Id
select name from sysobjects where type='U' _Cy:]2o
21、说明:列出表里的所有的 v)f7};"z
select name from syscolumns where id=object_id('TableName') `_5GG3@Ff
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 cBYfXI0`
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type Eq^uKi
显示结果: 3L_I[T$s
type vender pcs TwvAj#j
电脑 A 1 LF?P>
1%-
电脑 A 1 Sd))vS^g
光盘 B 2 w?mEuXc
光盘 A 2 F52B~@.
手机 B 3 _Mc>W0'5@
手机 C 3 C}?0`!Cc%
23、说明:初始化表table1 ~AG$5!
TRUNCATE TABLE table1 ]h!`IX
24、说明:选择从10到15的记录 [4+q+
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 3+xy4G@L
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三、技巧 p T[gdhc
1、1=1,1=2的使用,在SQL语句组合时用的较多 K"<*a"1I
"where 1=1" 是表示选择全部 "where 1=2"全部不选, -6=<#9R
如: )9=(|Lp
if @strWhere !='' C+F*690h
begin m"-[".-l-
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere .5> 20\b2
end ,WWj-X|+=
else +m,!e*g
begin Ybg-"w
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' YCy2 2@C
end PoShQR<
我们可以直接写成 t~M
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere OQ4c#V?
2、收缩数据库 R^MiP|?ZH
--重建索引 C+K=[
DBCC REINDEX Vv*NFJ |
DBCC INDEXDEFRAG T~gW3J
--收缩数据和日志 ] c}91
DBCC SHRINKDB JmOW~W
DBCC SHRINKFILE 5IqQ |/m<6
3、压缩数据库 fT
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dbcc shrinkdatabase(dbname) !q4x~G0d
4、转移数据库给新用户以已存在用户权限 %do1i W
exec sp_change_users_login 'update_one','newname','oldname' h4fLl3%H
go pKJK9@Ad
5、检查备份集 LD (C\
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' V/"}ku
6、修复数据库 TSL9ax4j
ALTER DATABASE [dvbbs] SET SINGLE_USER 7\/5r.
GO znZ7*S >6\
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ~# 7wdP
GO beZ(o?uK
ALTER DATABASE [dvbbs] SET MULTI_USER UQd6/mD`e
GO noNm^hFL
7、日志清除 q]<xMg#nu
SET NOCOUNT ON ,
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DECLARE @LogicalFileName sysname, */ OI*{Q
@MaxMinutes INT, %85Icg
@NewSize INT :#="%
USE tablename -- 要操作的数据库名 |$hgT K[L
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 I__ 4I{nI
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ;RN8\re
@NewSize = 1 -- 你想设定的日志文件的大小(M) m-1?\bs
-- Setup / initialize _MYx%Z
DECLARE @OriginalSize int FUeq
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SELECT @OriginalSize = size *+lsZ8'^C
FROM sysfiles lr('k`KOQ
WHERE name = @LogicalFileName LxJ6M/".
SELECT 'Original Size of ' + db_name() + ' LOG is ' + &1)xoZ'\
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + *M~.3$NN
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' EychR/s
FROM sysfiles rhY_|bi4P
WHERE name = @LogicalFileName K5ZnS`c;
CREATE TABLE DummyTrans uhn%lV]
(DummyColumn char (8000) not null) s` >H
DECLARE @Counter INT, B}*V%}:)
@StartTime DATETIME, -G ?%QG`v
@TruncLog VARCHAR(255) A['uD<4b
SELECT @StartTime = GETDATE(), y7zkAXhJ
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' IG.f=+<0
DBCC SHRINKFILE (@LogicalFileName, @NewSize) HdQj?f3
EXEC (@TruncLog) Li`hdrO'ii
-- Wrap the log if necessary. f =_^>>.
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired a&/HSf_G
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) U6WG?$x
AND (@OriginalSize * 8 /1024) > @NewSize rS~qi}4X
BEGIN -- Outer loop. VEh]p5D
SELECT @Counter = 0 PHR#>ZD
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) N&;\PfG
BEGIN -- update JmWR{du
INSERT DummyTrans VALUES ('Fill Log') Uh6mGLz*&
DELETE DummyTrans {y );vHf$
SELECT @Counter = @Counter + 1 w@N{@tG
END fwmLJ5o
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EXEC (@TruncLog) L:U4N*
END ^o%_W0_r
SELECT 'Final Size of ' + db_name() + ' LOG is ' + fuSq ={]
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + /GsrGX8
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 0 K3Hf^>m
FROM sysfiles jmW^`%;7
WHERE name = @LogicalFileName :|XCnK0
DROP TABLE DummyTrans `*9EKj
SET NOCOUNT OFF SWoEt1w
8、说明:更改某个表 irFc}.dI
exec sp_changeobjectowner 'tablename','dbo' -h\@RC
9、存储更改全部表 'yT`ef
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch &|z544
@OldOwner as NVARCHAR(128), ag]*DsBt
@NewOwner as NVARCHAR(128) \8_V(lU
AS &,uC9$
DECLARE @Name as NVARCHAR(128) J'7 y
DECLARE @Owner as NVARCHAR(128) =49o U
DECLARE @OwnerName as NVARCHAR(128) !d4HN.a7+u
DECLARE curObject CURSOR FOR #1l7FT?q
select 'Name' = name, 5 LMj!)3
'Owner' = user_name(uid) /Nqrvy=
from sysobjects >6K4b/.5w
where user_name(uid)=@OldOwner m'.T2e.u
order by name 4]"w b5%
OPEN curObject n2na9dX)w
FETCH NEXT FROM curObject INTO @Name, @Owner [a D:A
WHILE(@@FETCH_STATUS=0) r
}
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BEGIN B007x{-L
if @Owner=@OldOwner Dh8(HiXf:
begin -M`D>
set @OwnerName = @OldOwner + '.' + rtrim(@Name) CveWl$T12
exec sp_changeobjectowner @OwnerName, @NewOwner Rkr^Z?/GH
end 1nXqi)&?;
-- select @name,@NewOwner,@OldOwner 1,u{&%yL"w
FETCH NEXT FROM curObject INTO @Name, @Owner QJ M(UfHUD
END (wlfMiO
close curObject z\h,SX<U
deallocate curObject W8uVd zQ
GO qj;l,Kua
10、SQL SERVER中直接循环写入数据 {3SdX
declare @i int 1HXlHic
set @i=1 )v-Cj_W5]"
while @i<30 ;Bnr='[
begin x?>!UqgkY
insert into test (userid) values(@i) P7Z<0Dt\}
set @i=@i+1 o~}1oN
end yr{5Rp05=
小记存储过程中经常用到的本周,本月,本年函数 ?k
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Dateadd(wk,datediff(wk,0,getdate()),-1) bQ=s8'
Dateadd(wk,datediff(wk,0,getdate()),6) YZ{jP?x
Dateadd(mm,datediff(mm,0,getdate()),0) !SN WB
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) t!l/` e%J
Dateadd(yy,datediff(yy,0,getdate()),0) |%3O)B
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) z-)*Q
上面的SQL代码只是一个时间段 7n<#y;wo
Dateadd(wk,datediff(wk,0,getdate()),-1) }RDb1~6C
Dateadd(wk,datediff(wk,0,getdate()),6) Z3I L8
就是表示本周时间段. hC|KH}aCR)
下面的SQL的条件部分,就是查询时间段在本周范围内的: IKtiR8
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ~e+0c'n\
而在存储过程中 rkP4<E-M
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) q'fPNQg
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) (-#rFO5~l