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。 df{?E):
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一、基础 D(z#)oDr
1、说明:创建数据库 AB
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CREATE DATABASE database-name (~@.9&cBD
2、说明:删除数据库 S1k*"><
drop database dbname erI&XI
3、说明:备份sql server |@d(2f8
--- 创建 备份数据的 device %<~Ewno T
USE master THl:>s
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' _9oKW;7f7
--- 开始 备份 4#t'1tzu#
BACKUP DATABASE pubs TO testBack &"u(0q
4、说明:创建新表 7Kym|Zg
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 2NFk#_9e~
根据已有的表创建新表: !fs ~ >
A:create table tab_new like tab_old (使用旧表创建新表) %g*nd#wG
B:create table tab_new as select col1,col2... from tab_old definition only K-YxZAf
5、说明:删除新表 9#H0|zL
drop table tabname E[hSL#0
6、说明:增加一个列 /A5=L<T6F
Alter table tabname add column col type czw:xG!&
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。 ^uo,LTq+
7、说明:添加主键: Alter table tabname add primary key(col) Q3=X#FQ
说明:删除主键: Alter table tabname drop primary key(col) NO/$}vw
8、说明:创建索引:create [unique] index idxname on tabname(col....) 9u~C?w
删除索引:drop index idxname ?23J(;)s
注:索引是不可更改的,想更改必须删除重新建。 )^UqB0C6^
9、说明:创建视图:create view viewname as select statement dLQp"vs $
删除视图:drop view viewname A?tCa*b^
10、说明:几个简单的基本的sql语句 6rS
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选择:select * from table1 where 范围 ,%Pn.E* r;
插入:insert into table1(field1,field2) values(value1,value2) *7*_QW%?A
删除:delete from table1 where 范围 TaF*ZT2
更新:update table1 set field1=value1 where 范围 n4?;!p<F
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! }?b\/l<
排序:select * from table1 order by field1,field2 [desc] U>IsmF>m
总数:select count as totalcount from table1 bSM|"
求和:select sum(field1) as sumvalue from table1 {?
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平均:select avg(field1) as avgvalue from table1 )~P<ruk>,C
最大:select max(field1) as maxvalue from table1 FoIK, MdJ
最小:select min(field1) as minvalue from table1 DN8I[5O
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11、说明:几个高级查询运算词 Jv(E'"H
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A: UNION 运算符 "=s dn
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。 d+Mogku2
B: EXCEPT 运算符 ?n<sN"
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。 w8>lWgN
C: INTERSECT 运算符 7d{xXJ-
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。 ^`-Hg= d
注:使用运算词的几个查询结果行必须是一致的。 %jUZc:06
12、说明:使用外连接 2+|r*2_glo
A、left outer join: Gj#BG49g2
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。 )p!")
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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 "6e3Mj\
B:right outer join: 1>_$O|dE
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 -8:O?]+Q/
C:full outer join: tIA)LF
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 lYS4Q`z$
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二、提升 AED
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1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) D9(4%^HxV1
法一:select * into b from a where 1<>1 uPFbKSJj
法二:select top 0 * into b from a 48gpXcc@|
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) z:n
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insert into b(a, b, c) select d,e,f from b; R]kH$0`
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) Q1h v2*/U
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 N9c#N%cu
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. T~>&m~} +
4、说明:子查询(表名1:a 表名2:b) U:/_T>f%
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) v@X[0J_8
5、说明:显示文章、提交人和最后回复时间 Mc
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b JjAO9j%
6、说明:外连接查询(表名1:a 表名2:b) }WQ:Rmi
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c $~EY:
7、说明:在线视图查询(表名1:a ) .GnoK?
select * from (SELECT a,b,c FROM a) T where t.a > 1; 3,+UsB%
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 RXPl~]k#i
select * from table1 where time between time1 and time2 ;?o"{mbb
select a,b,c, from table1 where a not between 数值1 and 数值2 [woxCfSA
9、说明:in 的使用方法 a`||ePb|W~
select * from table1 where a [not] in ('值1','值2','值4','值6') y9: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 "Q23s"
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ~O~we
11、说明:四表联查问题: '?|.#D#-c
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 ..... [o'}R`5)
12、说明:日程安排提前五分钟提醒 +w?1<Z
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 v|kL7t)}
13、说明:一条sql 语句搞定数据库分页 QD[l 6
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 wZ8LY;
14、说明:前10条记录 `Q^Vm3h
select top 10 * form table1 where 范围 t/"9LMKs?
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.) ,"5p=JX`
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) <RkJ7Z^
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 is-{U?-
(select a from tableA ) except (select a from tableB) except (select a from tableC) v2#qs*sW8
17、说明:随机取出10条数据 Zfr?(y+3
select top 10 * from tablename order by newid() *
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18、说明:随机选择记录 el0W0T
select newid() (7aE!r\Ab
19、说明:删除重复记录 Bq:: 5,v
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 7"_gX
20、说明:列出数据库里所有的表名 =1kjKE !
select name from sysobjects where type='U' 1n
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21、说明:列出表里的所有的 $r)nvf`\
select name from syscolumns where id=object_id('TableName') Y0OVzp9 b
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。 {QLqf
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 )3_g&&
显示结果: gtP;Qw'
type vender pcs Kib?JRYt
电脑 A 1 l\-(li
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电脑 A 1 YwM;G
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光盘 B 2 E?f*Z{~,
光盘 A 2 01^W Py9l
手机 B 3 j@s,5:;[
手机 C 3 \-s'H:
23、说明:初始化表table1 3412znM&
TRUNCATE TABLE table1 "V_PWEi
24、说明:选择从10到15的记录 _bq2h%G=8
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Eh;~y*k\
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三、技巧 65A>p:OO
1、1=1,1=2的使用,在SQL语句组合时用的较多 QO~TuC
"where 1=1" 是表示选择全部 "where 1=2"全部不选, z//6yr
如: P(r}<SM
if @strWhere !='' 80M4~'3
begin KK*"s^L
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere w4+bzdZ
end kjW`k?'s
else QPa&kl
begin {GH
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 1z(y>`ZBq
end >&9Iy"
我们可以直接写成 C>7k|;BvF
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere `qsn;
2、收缩数据库
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--重建索引 /SD2e@x{U
DBCC REINDEX :XZ
DBCC INDEXDEFRAG .~
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--收缩数据和日志 p>p=nL K
DBCC SHRINKDB QSy #k~
DBCC SHRINKFILE 0) lG~_q
3、压缩数据库 !$5U\"M
dbcc shrinkdatabase(dbname) Zt[1RMO
4、转移数据库给新用户以已存在用户权限 #/1,Cv yj
exec sp_change_users_login 'update_one','newname','oldname' gasl%&
go " mE<r2=@
5、检查备份集 Wc_Ph40C<_
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 8YBsYKC
6、修复数据库 F3a"SKMW
ALTER DATABASE [dvbbs] SET SINGLE_USER [w)6OT
GO 7<?v!vQ}-
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Hca)5$yL
GO jKu"Vi|j>
ALTER DATABASE [dvbbs] SET MULTI_USER A|@d4+
GO 2S8/
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7、日志清除 nmN6RGx
SET NOCOUNT ON 'bg%9}
DECLARE @LogicalFileName sysname, 9W7H",wR
@MaxMinutes INT, B)"WG7W E
@NewSize INT ~c3CyOab
USE tablename -- 要操作的数据库名 ZA ii"F
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 o*QhoDjc
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ziy~~J
@NewSize = 1 -- 你想设定的日志文件的大小(M) zn3i2MWS
-- Setup / initialize [w~1e)D
DECLARE @OriginalSize int e:.Xs
SELECT @OriginalSize = size _W*3FH
FROM sysfiles ,[^P
WHERE name = @LogicalFileName X;p,Wq#D'
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 4//Ww6W:
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + s 4}}MV3X
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' I)O-i_}L&K
FROM sysfiles c Ew/F0
WHERE name = @LogicalFileName ]0dp^%
CREATE TABLE DummyTrans Rm *"SG
(DummyColumn char (8000) not null) `h
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DECLARE @Counter INT, U]ouBG8/
@StartTime DATETIME, +Mv0X%(N
@TruncLog VARCHAR(255) `^afbW
SELECT @StartTime = GETDATE(), 8c3X9;a
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 2Sb~tTGz79
DBCC SHRINKFILE (@LogicalFileName, @NewSize) f5/ba9nI
EXEC (@TruncLog) q@u$I'`Bs
-- Wrap the log if necessary. h_d!G+-]
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired qx53,^2
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) Z!|nc.
AND (@OriginalSize * 8 /1024) > @NewSize /)y~%0
BEGIN -- Outer loop. /{1 xpR
SELECT @Counter = 0 mrd(\&EhA
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 4k$BqM1
BEGIN -- update JUU0Tx:`9)
INSERT DummyTrans VALUES ('Fill Log') )CXJRo`j0
DELETE DummyTrans |g4!Yd
SELECT @Counter = @Counter + 1 c#`Z[
END S3j/(BG
EXEC (@TruncLog) M* QqiE
END kAbT&Rm"
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 0 x"3
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + fwxyZBr
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' P/Sv^d5=e
FROM sysfiles i' |S
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WHERE name = @LogicalFileName K#F~$k|1B
DROP TABLE DummyTrans z6FG^
SET NOCOUNT OFF o~^hsm[44J
8、说明:更改某个表 D@4hQC\
exec sp_changeobjectowner 'tablename','dbo' A"z')
9、存储更改全部表 T?7ZF+yo6
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch OjeM#s#N!
@OldOwner as NVARCHAR(128), JYKA@sZHe
@NewOwner as NVARCHAR(128) [>?B`1;@
AS |TEf? <"c
DECLARE @Name as NVARCHAR(128) \kWceu}H,
DECLARE @Owner as NVARCHAR(128) Gz~P
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DECLARE @OwnerName as NVARCHAR(128) +\.gd L)
DECLARE curObject CURSOR FOR rMf& HX
select 'Name' = name, 4U>
'Owner' = user_name(uid) `t ZvIy*
from sysobjects :fpYraBM
where user_name(uid)=@OldOwner /k}vm3
order by name %t%+;(M9
OPEN curObject
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FETCH NEXT FROM curObject INTO @Name, @Owner D
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WHILE(@@FETCH_STATUS=0) O,xU+j~)
BEGIN Q} f=Ye(&}
if @Owner=@OldOwner kfA%%A
begin N9:xtrJ]_J
set @OwnerName = @OldOwner + '.' + rtrim(@Name) jt-ayLq
exec sp_changeobjectowner @OwnerName, @NewOwner WGVvBX7#
end b\VY)=U
-- select @name,@NewOwner,@OldOwner iu&'v
FETCH NEXT FROM curObject INTO @Name, @Owner u&
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END ]eP&r?B
close curObject MF]s(7U4`
deallocate curObject > -Jd@7-
GO tX Z5oG7
10、SQL SERVER中直接循环写入数据 vVZ@/D6w
declare @i int `Nu3s<O7CF
set @i=1 |7UR_(}KC
while @i<30 81H04L9K 7
begin 1c+[S]7rY
insert into test (userid) values(@i) -Vt*(L
set @i=@i+1 eSywWSdf0
end =1yU&
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小记存储过程中经常用到的本周,本月,本年函数 ^^)D!I"cA,
Dateadd(wk,datediff(wk,0,getdate()),-1) A^
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Dateadd(wk,datediff(wk,0,getdate()),6) H`aqpa"C
Dateadd(mm,datediff(mm,0,getdate()),0) nY}Ep\g
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) i v&:X3iB
Dateadd(yy,datediff(yy,0,getdate()),0) n>Q/XQXB
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) eA#J7=eC
上面的SQL代码只是一个时间段 AVi
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Dateadd(wk,datediff(wk,0,getdate()),-1) EQz`o+
Dateadd(wk,datediff(wk,0,getdate()),6) &kRkOjuk
就是表示本周时间段. +`_%U7p(
下面的SQL的条件部分,就是查询时间段在本周范围内的: SS@#$t:
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) #ra:^9;Es:
而在存储过程中 AXz'=T}{
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) )5)S8~Oc
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) B]InOlc47