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。 xjbI1qCfe
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一、基础 'yX\y
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1、说明:创建数据库 eUQmW^
CREATE DATABASE database-name sx=1pnP9`
2、说明:删除数据库 Yv]vl6<
drop database dbname !9
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3、说明:备份sql server {U_ ,y(V
--- 创建 备份数据的 device 6
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USE master lhYJectJa
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' #M!$CGi (
--- 开始 备份 w:%NEa,Z
BACKUP DATABASE pubs TO testBack TxK
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4、说明:创建新表 ,jC~U s<
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 5l8F.LtO\
根据已有的表创建新表: ];Noe9o
A:create table tab_new like tab_old (使用旧表创建新表) 9D\E0YG X/
B:create table tab_new as select col1,col2... from tab_old definition only :2c(.-[`
5、说明:删除新表 W)r|9G8T
drop table tabname >$rH,Er
6、说明:增加一个列 u->[y1JY
Alter table tabname add column col type )?SF IQ=
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。 Ne|CWUhO
7、说明:添加主键: Alter table tabname add primary key(col) ? 3fnt"
说明:删除主键: Alter table tabname drop primary key(col) 3lWGa7<4Z
8、说明:创建索引:create [unique] index idxname on tabname(col....) }rmr0Bh
删除索引:drop index idxname <Rw2F?S~)n
注:索引是不可更改的,想更改必须删除重新建。 hk5!$#^
9、说明:创建视图:create view viewname as select statement GOdWc9Ta!
删除视图:drop view viewname |;a$
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10、说明:几个简单的基本的sql语句 -
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选择:select * from table1 where 范围 >qy62:co
插入:insert into table1(field1,field2) values(value1,value2) <(Ar[Rp
删除:delete from table1 where 范围 0AWxU?$A4
更新:update table1 set field1=value1 where 范围 ],!}|
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! WP\kg\o
排序:select * from table1 order by field1,field2 [desc] <ndY6n3
总数:select count as totalcount from table1 >V)#y$Z
求和:select sum(field1) as sumvalue from table1 -:_3N2U=+
平均:select avg(field1) as avgvalue from table1 8~,zv_Pl
最大:select max(field1) as maxvalue from table1 %u9Q`
最小:select min(field1) as minvalue from table1 a+v.(mCG
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11、说明:几个高级查询运算词 ~P}ng{x4z
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A: UNION 运算符 1
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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。 `*Wg&u
B: EXCEPT 运算符 Es}`SIe/
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。 VgbT/v
C: INTERSECT 运算符 y]R+/
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。 `Zmdlp@
注:使用运算词的几个查询结果行必须是一致的。 DQu)?Rsk
12、说明:使用外连接 EY)?hJS,
A、left outer join: cY!Pv
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。 FU*q9s `
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 @||nd,i`n~
B:right outer join: _
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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。 WaX!y$/z
C:full outer join: 4yTgH0(T
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 Yevd h<
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二、提升 hd/'>]
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ~S~+'V,d
法一:select * into b from a where 1<>1 3e-E/6zH6
法二:select top 0 * into b from a ?)<zzL",
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) %'. x vC
insert into b(a, b, c) select d,e,f from b; QS4~":D/C
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) k]-Q3V
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 'bH~KK5
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. WCqa[=v)t
4、说明:子查询(表名1:a 表名2:b) hc]p^/H
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) XLYGhM
5、说明:显示文章、提交人和最后回复时间 V#Y"0l+~
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b inq
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6、说明:外连接查询(表名1:a 表名2:b) {ktwX\z
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c %)d7iT~M
7、说明:在线视图查询(表名1:a ) %<O~eXY
select * from (SELECT a,b,c FROM a) T where t.a > 1; u+6L>7t88I
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 OM7AK
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select * from table1 where time between time1 and time2 vaVV1
select a,b,c, from table1 where a not between 数值1 and 数值2 N3KI6p6 \
9、说明:in 的使用方法 3;uLBuZOCN
select * from table1 where a [not] in ('值1','值2','值4','值6') XN\rq=
10、说明:两张关联表,删除主表中已经在副表中没有的信息 g#1Y4
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 6N Ogi
11、说明:四表联查问题: !lZ}kz0
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... {5ehm
12、说明:日程安排提前五分钟提醒 :1"k`AG
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 @x[A^
13、说明:一条sql 语句搞定数据库分页 \fvm6$ rZ^
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 Y>8JHoV
14、说明:前10条记录 Ck
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select top 10 * form table1 where 范围 CZy3]O"qW
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.) ~`$P-^u88X
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) p7izy$Wc
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 &b%2Jx[+
(select a from tableA ) except (select a from tableB) except (select a from tableC) y
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17、说明:随机取出10条数据 ?y"M>#
select top 10 * from tablename order by newid() tU!Yg"4Q
18、说明:随机选择记录 T>hm\ !
select newid() +.rOqkxJ
19、说明:删除重复记录 W|sU[dxZ
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) R7h3O0@!
20、说明:列出数据库里所有的表名 aN,?a@B
select name from sysobjects where type='U' v7hw% 9(=
21、说明:列出表里的所有的 Q$k#q<+0
select name from syscolumns where id=object_id('TableName') +`$$^x
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。 Vvfd?G"
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 2r+nr
显示结果: *<"{(sAvk
type vender pcs 79o=HiOF99
电脑 A 1 kf |J
电脑 A 1 wQ9@
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光盘 B 2 +n%8*F&
光盘 A 2 !HhF*Rlr
手机 B 3 UV{})T*s
手机 C 3 'V <ZmJ2
23、说明:初始化表table1 .*W7Z8!e
TRUNCATE TABLE table1 {F\P3-ub
24、说明:选择从10到15的记录 d{ B0a1P
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc $S2
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三、技巧 [
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1、1=1,1=2的使用,在SQL语句组合时用的较多 Lm1JiPs d
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Are0Nj&?
如: [a~@6*=
if @strWhere !='' S+^hK1jL
begin `fG<iBD
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 7:JGr O
end 7;r3Bxa
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else S&'s/jB
begin a^[s[j#^,
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' J{XRltI+
end }6{00er
我们可以直接写成 $?[pcgv
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 1L?W+zMO
2、收缩数据库 6O0aGJ,H
--重建索引 #8BI`.t)j
DBCC REINDEX N_+D#Z.g
DBCC INDEXDEFRAG GyFA1%(o
--收缩数据和日志 Q+_z*
DBCC SHRINKDB `@u9 fx.
DBCC SHRINKFILE ?hURNlR_Q
3、压缩数据库 i 2[8^o`_
dbcc shrinkdatabase(dbname) J?4dafkw
4、转移数据库给新用户以已存在用户权限 2jkma :$'
exec sp_change_users_login 'update_one','newname','oldname' I,]q;lEMt
go zQu9LN
5、检查备份集 OKu~Nb*
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ?UeV5<TewS
6、修复数据库 aJ1{9 5ea
ALTER DATABASE [dvbbs] SET SINGLE_USER 3e\IRF xzb
GO A
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DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK OekE]`~w
GO I@#IXH?6
ALTER DATABASE [dvbbs] SET MULTI_USER y Tk1
GO M@*Y&(~
7、日志清除 {QOy'
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SET NOCOUNT ON Wu8zK=Ve(
DECLARE @LogicalFileName sysname, wqzpFPk(
@MaxMinutes INT, 5HY0 *\
@NewSize INT )N\ BC
USE tablename -- 要操作的数据库名 X_,R!$wbg:
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 KAu>U3\/
@MaxMinutes = 10, -- Limit on time allowed to wrap log. xv%]g=Q
@NewSize = 1 -- 你想设定的日志文件的大小(M) lJx5scN[
-- Setup / initialize <HpUP!q8v
DECLARE @OriginalSize int $) qL=kR
SELECT @OriginalSize = size P1Iy>%3
FROM sysfiles N!-P2) @
WHERE name = @LogicalFileName ~Ra8(KocD
SELECT 'Original Size of ' + db_name() + ' LOG is ' + zzd PR}VG
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + D$TpT
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' (eHTXk*V`
FROM sysfiles |~rKD c
WHERE name = @LogicalFileName 3Lv5>[MnN
CREATE TABLE DummyTrans HTm`_}G9
(DummyColumn char (8000) not null) 1vJj?Uqc
DECLARE @Counter INT, rcH{"\F_/
@StartTime DATETIME, h$%h w+"4
@TruncLog VARCHAR(255) ^D ;EbR
SELECT @StartTime = GETDATE(), )gAqWbkB
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' j;-2)ZLm
DBCC SHRINKFILE (@LogicalFileName, @NewSize) y,qn 9
EXEC (@TruncLog) Dg}EI^ d
-- Wrap the log if necessary. WB `h)
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired oc[z dIk
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) t=jG $A
AND (@OriginalSize * 8 /1024) > @NewSize HLc3KYIk
BEGIN -- Outer loop. i#*lK7
SELECT @Counter = 0 4VC8#x1
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) }I18|=TB
BEGIN -- update l?L s=J*
INSERT DummyTrans VALUES ('Fill Log') %D%
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DELETE DummyTrans gebL6oc%
SELECT @Counter = @Counter + 1 Wo,93]
END \i<7Lk
EXEC (@TruncLog) GBT219Z@8
END \vS >jB
SELECT 'Final Size of ' + db_name() + ' LOG is ' + x]4>f[>*>
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ocpM6b.fK
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 6#a82_
FROM sysfiles @,LU!#y(
WHERE name = @LogicalFileName VAe[x
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DROP TABLE DummyTrans lfr^NxO U
SET NOCOUNT OFF :EH>&vm
8、说明:更改某个表 JE<h
exec sp_changeobjectowner 'tablename','dbo' J2Qt! -
9、存储更改全部表 `v'yGsIV
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ZzP&Zrm
@OldOwner as NVARCHAR(128), g(G$*#}o8A
@NewOwner as NVARCHAR(128) 5s>>]
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AS Zt9ld=T
DECLARE @Name as NVARCHAR(128) b.9[Vf_G
DECLARE @Owner as NVARCHAR(128) xP27j_*m>
DECLARE @OwnerName as NVARCHAR(128) !HeQMz
DECLARE curObject CURSOR FOR p=|S%
select 'Name' = name, \c!e_rZ
'Owner' = user_name(uid) RPjw12Ly
from sysobjects U_Q;WPJ
where user_name(uid)=@OldOwner >ZU)bnndA
order by name *<}R=X.
OPEN curObject xZ
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FETCH NEXT FROM curObject INTO @Name, @Owner ]K%d
WHILE(@@FETCH_STATUS=0) &MB1'~Q,hq
BEGIN $Yw~v36`t/
if @Owner=@OldOwner $FZcvo3@*S
begin j zwHb'4B3
set @OwnerName = @OldOwner + '.' + rtrim(@Name) `B$Pk0>5r
exec sp_changeobjectowner @OwnerName, @NewOwner 0oqOX
end R0bgt2J
-- select @name,@NewOwner,@OldOwner APCE}%1U
FETCH NEXT FROM curObject INTO @Name, @Owner Tr;&bX5]H
END ='-/JH~
close curObject ]u:Ij|.'y0
deallocate curObject 8m#y>`
GO $4^h>x
10、SQL SERVER中直接循环写入数据 {!! 8 *ix
declare @i int ~B7<Yg
set @i=1 R 0G!5>1i
while @i<30 ih|&q
begin 8N3rYx;d~
insert into test (userid) values(@i) (UTA3Db
set @i=@i+1 Qo*OC 9E`
end :'[ha$
小记存储过程中经常用到的本周,本月,本年函数 o> &-B.zq
Dateadd(wk,datediff(wk,0,getdate()),-1)
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Dateadd(wk,datediff(wk,0,getdate()),6) RVF<l?EI4R
Dateadd(mm,datediff(mm,0,getdate()),0) FV/lBWiQQ
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) Z|A+\#'
Dateadd(yy,datediff(yy,0,getdate()),0) p<y\^a
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) ^Cj3\G4,
上面的SQL代码只是一个时间段 ,L-V?B(UQ
Dateadd(wk,datediff(wk,0,getdate()),-1) zy|h1.gd
Dateadd(wk,datediff(wk,0,getdate()),6) S %wdXe
就是表示本周时间段. =4OV
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下面的SQL的条件部分,就是查询时间段在本周范围内的: z$Qy<_l
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ]?NiY:v
而在存储过程中 G-#rWZ&
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) GC(QV}9z"
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) gf^y3F[\