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。 P0UR{tK
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一、基础 6Emn@Mn=
1、说明:创建数据库 S(=@2A+;
CREATE DATABASE database-name c:${qY:!
2、说明:删除数据库 n l5+#e*\
drop database dbname m#h`iW
3、说明:备份sql server $I5|rB/4?
--- 创建 备份数据的 device MKtI3vi?
USE master $Y/z+ea
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 2K~v`c*4
--- 开始 备份 XzAXcxC6G
BACKUP DATABASE pubs TO testBack 3\2&?VAjR
4、说明:创建新表 >(:3H+
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) z{R
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根据已有的表创建新表: &Zz&VwWR
A:create table tab_new like tab_old (使用旧表创建新表) 8h
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B:create table tab_new as select col1,col2... from tab_old definition only iu{y.}?
5、说明:删除新表 @G&oUhS
drop table tabname GUQ3XF\
6、说明:增加一个列 ccv
Alter table tabname add column col type I>MLI=[Kg
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 r[E #JHw
7、说明:添加主键: Alter table tabname add primary key(col) p&}m')
说明:删除主键: Alter table tabname drop primary key(col) ufR|V-BWx
8、说明:创建索引:create [unique] index idxname on tabname(col....) d Np%=gIj
删除索引:drop index idxname [<+T@"y
注:索引是不可更改的,想更改必须删除重新建。 Q*1Avy6]
9、说明:创建视图:create view viewname as select statement li3X}
删除视图:drop view viewname pTAm}
10、说明:几个简单的基本的sql语句 ?r;F'%N=
选择:select * from table1 where 范围 ,,FhE
插入:insert into table1(field1,field2) values(value1,value2) c'$y_]
删除:delete from table1 where 范围 Ez
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更新:update table1 set field1=value1 where 范围 a[t"J*0
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! jhT/}"v
排序:select * from table1 order by field1,field2 [desc] DI{Qs[
总数:select count as totalcount from table1 i(rYc
求和:select sum(field1) as sumvalue from table1 tli*3YIw
平均:select avg(field1) as avgvalue from table1 |QrVGm@2
最大:select max(field1) as maxvalue from table1 ,ig`'U
最小:select min(field1) as minvalue from table1 E=.J*7
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11、说明:几个高级查询运算词 H(
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A: UNION 运算符 Z){fie4WM
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。 iLdUus!
B: EXCEPT 运算符 g9GPyU
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。 =j_4!^
C: INTERSECT 运算符 ml~)7J
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。 #E4oq9{0*W
注:使用运算词的几个查询结果行必须是一致的。 ~Q- /O~
12、说明:使用外连接 =)#XZ[#F
A、left outer join: B"7~[,he
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。 a# 0*#&?7@
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 $y)tcVc
B:right outer join: %PVu>^
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 y] Q/(O
C:full outer join: D$hK
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。 0Dd8c\J
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二、提升 <{V{2V#
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) dn5t7D^x
法一:select * into b from a where 1<>1 n`Ypv{+ {%
法二:select top 0 * into b from a #;2kN
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) <Rt0
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insert into b(a, b, c) select d,e,f from b; H2_6m5[&,
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) j"0TAYmXwu
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 TIV|7nKL
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. <95*z @
4、说明:子查询(表名1:a 表名2:b) ylmVmHmc
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) * se),CP!s
5、说明:显示文章、提交人和最后回复时间 UuJ gB)
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b q!d7Ms{q
6、说明:外连接查询(表名1:a 表名2:b) ]VVx2ERs
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Lz-(1~o
7、说明:在线视图查询(表名1:a ) Or1ikI"
select * from (SELECT a,b,c FROM a) T where t.a > 1; <t *3w
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 Y
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select * from table1 where time between time1 and time2 gZ(\/m8Z
select a,b,c, from table1 where a not between 数值1 and 数值2 -OQ6;A"#
9、说明:in 的使用方法 ]xJ2;{JWsO
select * from table1 where a [not] in ('值1','值2','值4','值6') J@Nq
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)I%1T_c
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) "jq F
11、说明:四表联查问题: >+BLD
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 ..... X)Rh&ui
12、说明:日程安排提前五分钟提醒 YZ0Q?7l7
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 &53LJlL
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13、说明:一条sql 语句搞定数据库分页 )q+;+J`>
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 E-rGOm" m
14、说明:前10条记录 \p iz Vt
select top 10 * form table1 where 范围 cTJG1'm
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.) (
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) EU7mP
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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 w3Qil[rg
(select a from tableA ) except (select a from tableB) except (select a from tableC) n\scOM)3
17、说明:随机取出10条数据 X{5(i3?S
select top 10 * from tablename order by newid() #w[Ie+
18、说明:随机选择记录 \T!tUd
select newid() S#D6mg$Z,
19、说明:删除重复记录 JOq&(AZe
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 0bIhP,4&
20、说明:列出数据库里所有的表名 grCz@i
select name from sysobjects where type='U' CwzDkr&QC_
21、说明:列出表里的所有的 |A
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select name from syscolumns where id=object_id('TableName') k8sjW!2
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 'k$j^|r>
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 [{-;cpM\
显示结果: ue6&)7:~
type vender pcs *Q3q(rdrp
电脑 A 1 gDsb~>rb|
电脑 A 1 ,3ivB8
光盘 B 2 d>Np; "
光盘 A 2 =
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手机 B 3 _AVP1
手机 C 3 SQBe}FlktK
23、说明:初始化表table1 Xpf:I
TRUNCATE TABLE table1 4q^'MZm1
24、说明:选择从10到15的记录 DmpD`^?-L
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc #F >R5 D
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三、技巧 g"v-hTx
1、1=1,1=2的使用,在SQL语句组合时用的较多 G
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, k'{Bhi4
如: =qTmFszT
if @strWhere !='' 4}HY= 0Um
begin v+`gQXJ"G
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere =I9RM9O<
end 7pz #%Hf
else QK/~lN
begin n|I5ylt
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' [[0u|`T/
end ^5*9BwH`
我们可以直接写成 u"1Zv!
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere Hk|wO:7Be
2、收缩数据库 g~$cnU
--重建索引 |"EQyV
DBCC REINDEX \ssqIRk
DBCC INDEXDEFRAG w97%5[-T
--收缩数据和日志 2~*.X^dR
DBCC SHRINKDB eB*0})
DBCC SHRINKFILE h}jE=T5Hc
3、压缩数据库 kC-OZ VoO
dbcc shrinkdatabase(dbname) D~JrO]mi
4、转移数据库给新用户以已存在用户权限 r5\|%5=J
exec sp_change_users_login 'update_one','newname','oldname' ZncJ
go io(Rb\#"
5、检查备份集 b$1W>
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' <MBpV^Y}
6、修复数据库 ]eZrb%B.
ALTER DATABASE [dvbbs] SET SINGLE_USER 4brKAqg.
GO 4XXuj
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK OB5`a,5dI
GO >hmBV7nR
ALTER DATABASE [dvbbs] SET MULTI_USER \$[S=&E
GO S+&Bf ~~D
7、日志清除 "_T8Km008
SET NOCOUNT ON Ves
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DECLARE @LogicalFileName sysname, jpek=4E
@MaxMinutes INT, P+nd?:cz
@NewSize INT h#rziZ(
USE tablename -- 要操作的数据库名 +&h<:/ V
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 vCS D1~V_
@MaxMinutes = 10, -- Limit on time allowed to wrap log. o79EDPX
@NewSize = 1 -- 你想设定的日志文件的大小(M) hV]]%zwR+
-- Setup / initialize Gg=Y}S7:
DECLARE @OriginalSize int yJAz#~PO/
SELECT @OriginalSize = size /KH,11)yc
FROM sysfiles gG6j>%y
WHERE name = @LogicalFileName o\;cXuh
SELECT 'Original Size of ' + db_name() + ' LOG is ' + v46 5Z
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + [GqQ6\
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' hMvLx>q3)
FROM sysfiles KN-)m ta&
WHERE name = @LogicalFileName E1-BB
CREATE TABLE DummyTrans m3i+b
(DummyColumn char (8000) not null) ]3iQpL
DECLARE @Counter INT, V*w~Sr%
@StartTime DATETIME, G :JQ_w
@TruncLog VARCHAR(255) of k@.TmO
SELECT @StartTime = GETDATE(), R9`37(c9+
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' CDU$Gi
DBCC SHRINKFILE (@LogicalFileName, @NewSize) %qqX-SF0C
EXEC (@TruncLog) .~t.B!rVSB
-- Wrap the log if necessary. 2Ub!wee
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ,4tuWO)"
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) !O}^ Y
AND (@OriginalSize * 8 /1024) > @NewSize a08`h.dyN
BEGIN -- Outer loop. V 0M&D,
SELECT @Counter = 0 I c 2R\}q
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) Z0I>PBL@l
BEGIN -- update ;Wu6f"+Y#
INSERT DummyTrans VALUES ('Fill Log') 8\{1y:|
DELETE DummyTrans _gl7Ma
SELECT @Counter = @Counter + 1 yTb#V"eR
END JcDcYB
EXEC (@TruncLog) 1Vy8TV3D
END Yy3g7!K5E
SELECT 'Final Size of ' + db_name() + ' LOG is ' + osdl dS
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + tlJ@@v&=
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 7)#8p@Q
FROM sysfiles T@)|0M
WHERE name = @LogicalFileName Qaeg3f3F3
DROP TABLE DummyTrans E+!A0!1
SET NOCOUNT OFF A,;V|jv9
8、说明:更改某个表 u?B9zt%$-m
exec sp_changeobjectowner 'tablename','dbo' -)LiL
9、存储更改全部表 _^ny(zy(
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch nqMXE82
@OldOwner as NVARCHAR(128), Yg kd 1uI.
@NewOwner as NVARCHAR(128) $]t3pAI[H0
AS yrVk$k#6}
DECLARE @Name as NVARCHAR(128) %!r@l7<
DECLARE @Owner as NVARCHAR(128) U8gf_R'
DECLARE @OwnerName as NVARCHAR(128) ?6T\uzL +%
DECLARE curObject CURSOR FOR he\ pW5p
select 'Name' = name, LX2Re
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'Owner' = user_name(uid) o3OtG#g2
from sysobjects zo>@"uH4
where user_name(uid)=@OldOwner 8.m9 =+)8
order by name }s++^uX6
OPEN curObject !5XH.DYq!
FETCH NEXT FROM curObject INTO @Name, @Owner g/f^|:
WHILE(@@FETCH_STATUS=0) R Q2DTQ-$
BEGIN 3JJEj1O
if @Owner=@OldOwner @zGz8IF
begin UHT2a9rG
set @OwnerName = @OldOwner + '.' + rtrim(@Name) O=E?m=FR"
exec sp_changeobjectowner @OwnerName, @NewOwner #<*=) [
end wFX>y^ 1
-- select @name,@NewOwner,@OldOwner V|W[>/
FETCH NEXT FROM curObject INTO @Name, @Owner h1AZ+9
END `+0K~k|DC
close curObject EYXHxo
deallocate curObject BDiN*.w5
GO ^Ez`WP
10、SQL SERVER中直接循环写入数据 >Xv
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declare @i int `ZhS=ezgr
set @i=1 u]uZc~T
while @i<30 0 F-db
begin A$o7<Hx
insert into test (userid) values(@i) 0wnC"2GUX
set @i=@i+1 7Z[6_WD3
end ,?/AIL]_
小记存储过程中经常用到的本周,本月,本年函数 9T;DFUM
Dateadd(wk,datediff(wk,0,getdate()),-1) fIwG9cR
Dateadd(wk,datediff(wk,0,getdate()),6) *mtS\J
Dateadd(mm,datediff(mm,0,getdate()),0) 3 =-XA2zJ
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ]r.95|V*
Dateadd(yy,datediff(yy,0,getdate()),0) % db
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) V3v/hV:
上面的SQL代码只是一个时间段 J-d>#'Wb|
Dateadd(wk,datediff(wk,0,getdate()),-1) mP[Z lS~"
Dateadd(wk,datediff(wk,0,getdate()),6) /JbO $A
就是表示本周时间段. q)rxv7Iu\
下面的SQL的条件部分,就是查询时间段在本周范围内的: Mv\]uAT`
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) jWNF3\
而在存储过程中 &r0U9J
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) M>g%wg7Ah
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) i8|0zI