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。 ;RTrRh0v
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一、基础 '=@H2T6=
1、说明:创建数据库 !nqm ;96
CREATE DATABASE database-name Gh chfI.
2、说明:删除数据库 D| 8sjp4
drop database dbname uH~ TugQ~
3、说明:备份sql server +A.a~Stt
--- 创建 备份数据的 device @8x6#|D
USE master 3e!a>Gl*
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' )SlUQ7f>
--- 开始 备份 n8y ,{|
BACKUP DATABASE pubs TO testBack R-0_226
4、说明:创建新表 071 E%u,
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) u:qD*zOq
根据已有的表创建新表: ~L Bq5a
A:create table tab_new like tab_old (使用旧表创建新表) VAG+y/q
B:create table tab_new as select col1,col2... from tab_old definition only zN8&M<mTl
5、说明:删除新表 ^`B##9g~
drop table tabname E?;T:7.%
6、说明:增加一个列 _sCJ3ZJ
Alter table tabname add column col type Wtzj;GJj
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。 $=S'#^Z
7、说明:添加主键: Alter table tabname add primary key(col) cVv4gQD\
说明:删除主键: Alter table tabname drop primary key(col) (tz_D7c$F
8、说明:创建索引:create [unique] index idxname on tabname(col....)
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删除索引:drop index idxname Ke;X3j ]`
注:索引是不可更改的,想更改必须删除重新建。 5;i!PuL
9、说明:创建视图:create view viewname as select statement k(vEp]
删除视图:drop view viewname xs83S.fHg
10、说明:几个简单的基本的sql语句 !xx>
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选择:select * from table1 where 范围 \p=W4W/
插入:insert into table1(field1,field2) values(value1,value2) `!>dbR&1
删除:delete from table1 where 范围 ~_^o?NE,
更新:update table1 set field1=value1 where 范围 Yqz[sz5+m
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ky
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排序:select * from table1 order by field1,field2 [desc] ^|hRu{QW
总数:select count as totalcount from table1 KTAe~y
求和:select sum(field1) as sumvalue from table1 |
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平均:select avg(field1) as avgvalue from table1 ZE3ysLkm
最大:select max(field1) as maxvalue from table1 O+UV\
最小:select min(field1) as minvalue from table1 Eg-Mm4o
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11、说明:几个高级查询运算词 B$[%pm`'2
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A: UNION 运算符 ~IJZM`gN
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。 >7v.`m6?H
B: EXCEPT 运算符 g cK"
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。 N@du.d:
C: INTERSECT 运算符 SpTORR8
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。 XCi]()TZ_
注:使用运算词的几个查询结果行必须是一致的。 j*Wh;I+h
12、说明:使用外连接 '2qxcc o
A、left outer join: -aeo7C
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。 l1|,Lr
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 Gk]qE]hi
B:right outer join: E(4lu%
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。 ^*UfCoj9Z
C:full outer join: ?GD?J(S
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。 ]OCJ~Zw
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二、提升 n4_:#L?
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 'rq#q)1MT
法一:select * into b from a where 1<>1 E{]|jPdr
法二:select top 0 * into b from a 'Tan6Qa
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) mEc;-b
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insert into b(a, b, c) select d,e,f from b; g KmRjK
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) `J7Lecgo
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 7[.Q.3FL
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. q?]@' ^:;
4、说明:子查询(表名1:a 表名2:b) j'Q-*-3
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) ?`*-QG}
5、说明:显示文章、提交人和最后回复时间 s2v#evI`+
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b sq(063l
6、说明:外连接查询(表名1:a 表名2:b) en#g<on
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c )PoI~km
7、说明:在线视图查询(表名1:a ) Wv*BwiQ
select * from (SELECT a,b,c FROM a) T where t.a > 1; JE:n`l/p
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 m ?"%&|
select * from table1 where time between time1 and time2 /zP)2q^
select a,b,c, from table1 where a not between 数值1 and 数值2 T _9ZI|Jx
9、说明:in 的使用方法 $$;2jX"I
select * from table1 where a [not] in ('值1','值2','值4','值6') gwB>oi*OE
10、说明:两张关联表,删除主表中已经在副表中没有的信息 a:%5.!Vd
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) hv8[_p`>
11、说明:四表联查问题: {hq ;7
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 ..... ci NTYow
12、说明:日程安排提前五分钟提醒 {F9Qy0.*u
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 [tf^i:2
13、说明:一条sql 语句搞定数据库分页 GTIfrqT
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 iF_r'+j
14、说明:前10条记录 P;o>~Y>x
select top 10 * form table1 where 范围 +FKP5L}
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.) 2?7hUaHX
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) _M4v1Hr48
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 Ac(irPrD
(select a from tableA ) except (select a from tableB) except (select a from tableC) f<Um2YGW
17、说明:随机取出10条数据 >,]e[/p
select top 10 * from tablename order by newid() k@)m- K
18、说明:随机选择记录 =v`&iL~m
select newid() y^|3]G3
19、说明:删除重复记录 j%y+W{Q[
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) l
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20、说明:列出数据库里所有的表名 KXbYv62
select name from sysobjects where type='U' adr^6n6v
21、说明:列出表里的所有的 F$y FR
select name from syscolumns where id=object_id('TableName') h \cK
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 0BP~0z
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type H_f2:Za
显示结果: }fMFQA)
type vender pcs dv}R]f'
电脑 A 1 O|TwG:!
电脑 A 1 ^F0jI5j ).
光盘 B 2 [)6E)E`_e
光盘 A 2 @' :um
手机 B 3 ^^Q32XC,
手机 C 3 8jGoU9
23、说明:初始化表table1 `ip69 IF2*
TRUNCATE TABLE table1 %f(.OR)6{
24、说明:选择从10到15的记录 |oi49:NXn
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc v6Wf7)d/1
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三、技巧 19{?w6G<k
1、1=1,1=2的使用,在SQL语句组合时用的较多 N6
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, k)' z<EL6c
如: CIvT5^}
if @strWhere !='' 7Bd_/A($
begin 'R5l
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere nln[V$
end HZ4
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else I[IQFka}
begin OL"5A18;M
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' <l/Qf[V
end s/0FSv
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我们可以直接写成 oOSyOD
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere }'v?Qq
2、收缩数据库 F9J9pgVP
--重建索引 DJjDKVO5t
DBCC REINDEX >mSl~.I2
DBCC INDEXDEFRAG #@"rp]1xv
--收缩数据和日志 >ZsK5v
DBCC SHRINKDB w7V
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DBCC SHRINKFILE +NMSvu_?
3、压缩数据库 Z'm%3
dbcc shrinkdatabase(dbname) %--5bwZi
4、转移数据库给新用户以已存在用户权限 9TS=>
exec sp_change_users_login 'update_one','newname','oldname' -^Va]Lk
go <Py/uF|
5、检查备份集 D5vtZu!"
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' RtQfE+
6、修复数据库 emIbGkH
ALTER DATABASE [dvbbs] SET SINGLE_USER Pg C]@Q%
GO G"sc;nT
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK m 4LM10
GO RA67w&
ALTER DATABASE [dvbbs] SET MULTI_USER E?o8'r
GO pra&A2Y\
7、日志清除 +mv%z3"j;
SET NOCOUNT ON b#j5fEY
DECLARE @LogicalFileName sysname, #T`+~tW'|
@MaxMinutes INT, j".6
@NewSize INT l Nt o9
USE tablename -- 要操作的数据库名 [kkcV5I-
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 n}kz&,
@MaxMinutes = 10, -- Limit on time allowed to wrap log. D|#(zjl@
@NewSize = 1 -- 你想设定的日志文件的大小(M)
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-- Setup / initialize hG3Lj7)UH
DECLARE @OriginalSize int F4gc_>{|
SELECT @OriginalSize = size !qve1H4d2
FROM sysfiles t4f\0`jN
WHERE name = @LogicalFileName VO?NrKyeW
SELECT 'Original Size of ' + db_name() + ' LOG is ' + rrRC5h
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + "evV/Fg(
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' &"n9,$
FROM sysfiles SVz.d/3Y
WHERE name = @LogicalFileName }CqIKoX.
CREATE TABLE DummyTrans zKT<QM!`
(DummyColumn char (8000) not null) 8}@a?QS(&
DECLARE @Counter INT, -e\56%\~_
@StartTime DATETIME, Vk
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@TruncLog VARCHAR(255) ZA@"uqa 6b
SELECT @StartTime = GETDATE(), '2oBi6|X
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' vLS6Gb't
DBCC SHRINKFILE (@LogicalFileName, @NewSize) dBn.DU*B
EXEC (@TruncLog) &>t1A5
-- Wrap the log if necessary. mq9&To!
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired V@f#/"u'
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) P .( X]+
AND (@OriginalSize * 8 /1024) > @NewSize Us.jyg7_c
BEGIN -- Outer loop. IW*.B6Hw8
SELECT @Counter = 0 j
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WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) syvi/6
BEGIN -- update 1!#ZEI C
INSERT DummyTrans VALUES ('Fill Log') Pw.+DA
DELETE DummyTrans /RJSkF+!
SELECT @Counter = @Counter + 1 \ziF(xTvqG
END FgaBwd^W
EXEC (@TruncLog) jX@9849@
END ]0E- lD0J
SELECT 'Final Size of ' + db_name() + ' LOG is ' + T+hW9pa)
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 7X>3WF
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' A'2:(m@{T
FROM sysfiles &ayoTE^0,
WHERE name = @LogicalFileName H;E{Fnarv
DROP TABLE DummyTrans HrxEC)V6#
SET NOCOUNT OFF 5~QB.m,>
8、说明:更改某个表 RL9P:]
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exec sp_changeobjectowner 'tablename','dbo' U"Oq85vY
9、存储更改全部表 :wm^04<i
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch EZV$1pa
@OldOwner as NVARCHAR(128), 1XRVbQt
@NewOwner as NVARCHAR(128) XzsK^E0R
AS 5H2|:GzUc
DECLARE @Name as NVARCHAR(128)
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DECLARE @Owner as NVARCHAR(128) Kfl+8UR5=
DECLARE @OwnerName as NVARCHAR(128) ^;bkU|(`6
DECLARE curObject CURSOR FOR ~qH@Kz\%
select 'Name' = name, ESI}+
'Owner' = user_name(uid) D%v yO_k
from sysobjects Wd#6Y}:
where user_name(uid)=@OldOwner ]B||S7idq
order by name XF6=xD
OPEN curObject zFIKB9NUn
FETCH NEXT FROM curObject INTO @Name, @Owner ]=Q'1%
WHILE(@@FETCH_STATUS=0) 0kfw8Lon
BEGIN [U0c
if @Owner=@OldOwner 9mZ1 a6,x
begin 0Jr<>7Q1
set @OwnerName = @OldOwner + '.' + rtrim(@Name) X)+N>8o?N
exec sp_changeobjectowner @OwnerName, @NewOwner ^xrR3m*d
end &-A7%"
-- select @name,@NewOwner,@OldOwner 1;V5b+b
FETCH NEXT FROM curObject INTO @Name, @Owner g&V.o5jIhc
END wd *Jq
close curObject uPPe"$
deallocate curObject gu!A:Q
GO arJ[.f9s
10、SQL SERVER中直接循环写入数据 OoNAW<
declare @i int Lif mYn[
set @i=1 \8!HZei
while @i<30 I(e>ff
begin ';%g^!lM
a
insert into test (userid) values(@i) WjB[e>
set @i=@i+1 W%o){+,
end C
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小记存储过程中经常用到的本周,本月,本年函数 * ?K=;$
Dateadd(wk,datediff(wk,0,getdate()),-1) b;{C1aa>}
Dateadd(wk,datediff(wk,0,getdate()),6) I$&/?ns@O
Dateadd(mm,datediff(mm,0,getdate()),0) PhQD}|S
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ;DTNw=
Dateadd(yy,datediff(yy,0,getdate()),0) aum,bm/0J
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) _%]H}N Q
上面的SQL代码只是一个时间段 %M`&}'6'
Dateadd(wk,datediff(wk,0,getdate()),-1) P?F:x=@'|
Dateadd(wk,datediff(wk,0,getdate()),6) !8$}]uWP
就是表示本周时间段. moGbBkO
下面的SQL的条件部分,就是查询时间段在本周范围内的: [*(MI 9WM
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) V*N9D>C
而在存储过程中 FYJB.lAT
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) shB(kb{{
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 2%I:s6r