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。 EC&19
;Q%19f3,6
ckkM)|kK
一、基础 pRfHbPV?
1、说明:创建数据库 (5\d[||9g
CREATE DATABASE database-name /-} p7AM
2、说明:删除数据库 MDXQj5s^
drop database dbname ` G/QJH{I
3、说明:备份sql server NhaeAD
$e
--- 创建 备份数据的 device ]4pC\0c
USE master Y K 62#;
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' [;\<
2 =H
--- 开始 备份 r4qV}-E
BACKUP DATABASE pubs TO testBack ^*T{-U'
4、说明:创建新表
Xv;ZA a
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) D_`)T;<Sp
根据已有的表创建新表: w+ )GM
A:create table tab_new like tab_old (使用旧表创建新表) xo@/k
B:create table tab_new as select col1,col2... from tab_old definition only {hp@j#
5、说明:删除新表 l=G#gKE
drop table tabname 'Rf#1ls#
6、说明:增加一个列 n@8{FoF
Alter table tabname add column col type qv >(
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 XT;IEZQZ
7、说明:添加主键: Alter table tabname add primary key(col) 7UnO/K7oB.
说明:删除主键: Alter table tabname drop primary key(col) Kh_>V m/
8、说明:创建索引:create [unique] index idxname on tabname(col....) vt7C
删除索引:drop index idxname +/ d8d
注:索引是不可更改的,想更改必须删除重新建。 E~U|v'GCd
9、说明:创建视图:create view viewname as select statement t@mw f3,
删除视图:drop view viewname /VOST^z!
10、说明:几个简单的基本的sql语句 i_9/!D
选择:select * from table1 where 范围 [aVJYr2
插入:insert into table1(field1,field2) values(value1,value2) +(hwe
jyC
删除:delete from table1 where 范围 sjbC~Te--
更新:update table1 set field1=value1 where 范围 eT
\Q
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! #pxet
排序:select * from table1 order by field1,field2 [desc] #hiDZ>nr
总数:select count as totalcount from table1 Y
.X-8
求和:select sum(field1) as sumvalue from table1 M>l+[U
平均:select avg(field1) as avgvalue from table1 jT_Tx\k
最大:select max(field1) as maxvalue from table1 yru}f;1
最小:select min(field1) as minvalue from table1 n!,TBCNX
'
=s*DL`0
[UrS%]OSR
&_TjRj"
11、说明:几个高级查询运算词 Q#AHEm{9;s
M(gWd8?#
)Syf5I
A: UNION 运算符 [\y>&"uk
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 ymJw{&^am
B: EXCEPT 运算符 :re(khZq#
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 (B4A$t
C: INTERSECT 运算符 >LZ)<-Mk
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。 00
,jneF
注:使用运算词的几个查询结果行必须是一致的。 ty8!"-V1
12、说明:使用外连接 JH,fg K+[
A、left outer join: X "r$,~
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 ?d'9TOlD
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c x"=q+sA
B:right outer join: X Ow^"=Oa[
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 MPw7!G(qj
C:full outer join: L{ ^@O0S
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 }Bg<Fm
icbYfgQ
YZ+g<HXB
二、提升 _A~gqOe
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) E^ti!4{<
法一:select * into b from a where 1<>1 \?IwR]@y
法二:select top 0 * into b from a \Xp"I5
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 8xz7S
insert into b(a, b, c) select d,e,f from b; +=xRr?F
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 69w"$Vk
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 eNskuG|1
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Oc=PJf%D#
4、说明:子查询(表名1:a 表名2:b) lBC-G*#
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) zIm!8a
5、说明:显示文章、提交人和最后回复时间 &xT~;R^
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 0(6`dr_
6、说明:外连接查询(表名1:a 表名2:b) gx.]4v
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 3Q"+
#Ob
7、说明:在线视图查询(表名1:a ) [l{eJ/W
select * from (SELECT a,b,c FROM a) T where t.a > 1; r\D8_S_
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 :cz]8~i\
select * from table1 where time between time1 and time2 Q2PwO;E.`C
select a,b,c, from table1 where a not between 数值1 and 数值2 M- A}(r +J
9、说明:in 的使用方法 hS/'b$#
select * from table1 where a [not] in ('值1','值2','值4','值6') !~kzxY
10、说明:两张关联表,删除主表中已经在副表中没有的信息 g0$k_
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) f@g
11、说明:四表联查问题: t9l7
% +y
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 ..... VAzJclB
12、说明:日程安排提前五分钟提醒 i`spM<iR.
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 SZ){1Hu
13、说明:一条sql 语句搞定数据库分页 =l9#/G#R
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 CT`X~y10
14、说明:前10条记录 }Elce}
select top 10 * form table1 where 范围 1#uw^{n
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.) eF\C?4
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) J4X35H=Z
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 jzw?V9Ijb
(select a from tableA ) except (select a from tableB) except (select a from tableC) U /Fomu
17、说明:随机取出10条数据 Ji=iq=S7
select top 10 * from tablename order by newid() r $2
18、说明:随机选择记录 vGDo?X~#o
select newid() 9^olAfX`dB
19、说明:删除重复记录 oa7Hx<Y
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) MPc=cLv
20、说明:列出数据库里所有的表名 uwzT? C A6
select name from sysobjects where type='U' B\yq%m
21、说明:列出表里的所有的 p$<qT^]&
select name from syscolumns where id=object_id('TableName') a06q-3zw
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。 %tLq&tyeY
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 Jp0.h8i
显示结果: |0mI3r
type vender pcs _J!mhUA
电脑 A 1 'kK%sE
电脑 A 1 JR)rp3o-
光盘 B 2 \]El%j4
光盘 A 2 bc-)y3gHU
手机 B 3 }5Uf`pM8
手机 C 3 6Fb~`J~s
23、说明:初始化表table1 >S]')O$c
TRUNCATE TABLE table1 EUqG"h5#A{
24、说明:选择从10到15的记录 z`SkKn0f
Y
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc [t'"4
+Eg# 8/q
}lVUa{ubf
Mr(3]EfgO
三、技巧 e:<>
Yq+
1、1=1,1=2的使用,在SQL语句组合时用的较多 RdHR[Usm
"where 1=1" 是表示选择全部 "where 1=2"全部不选, `Mg
"!n`
如: yL-L2
if @strWhere !='' D$;/
l}s?
begin 2D"/k'iA
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere O/nS,Ux
end ,,gYU_V
else e+TNG &_
begin 5c8x:
e@
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' N5DS-gv
end Qt 2hb
我们可以直接写成 ^p/mJ1/s7
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 8),Y|4
2、收缩数据库 TH &B9
--重建索引 .VT,,0
DBCC REINDEX Is[0ri
DBCC INDEXDEFRAG 1\uS~RR
--收缩数据和日志 <Vb{QOgc;
DBCC SHRINKDB uip]K{/A!e
DBCC SHRINKFILE 1,,-R*x
3、压缩数据库 3}+
\&[
dbcc shrinkdatabase(dbname) S{6u\Vy
4、转移数据库给新用户以已存在用户权限 }p~%GA.=98
exec sp_change_users_login 'update_one','newname','oldname' &@+;]t
go e`^j_VnEH
5、检查备份集 |~Iw
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' FReK
6、修复数据库 T*m_rDDt
ALTER DATABASE [dvbbs] SET SINGLE_USER da@
.J9
GO v#xF;@G
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK |Oe6OCPf
GO Wt=[R 4=
ALTER DATABASE [dvbbs] SET MULTI_USER 2_Z60]
GO 9 pn1d.
7、日志清除 It[ ~0?+
SET NOCOUNT ON &PX'=UT
DECLARE @LogicalFileName sysname, 0'uj*Y{L
@MaxMinutes INT, p
WH u[Fu
@NewSize INT .anL}OA_q
USE tablename -- 要操作的数据库名 vNIQc "\-
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ,U}8(D~:
@MaxMinutes = 10, -- Limit on time allowed to wrap log. R#>E{[9
@NewSize = 1 -- 你想设定的日志文件的大小(M) "5Mo%cUp
-- Setup / initialize z~qQ@u|
DECLARE @OriginalSize int Qw:j2g2H7
SELECT @OriginalSize = size Alz#zBGb
FROM sysfiles ff0,K#-
WHERE name = @LogicalFileName &n|gPp77$
SELECT 'Original Size of ' + db_name() + ' LOG is ' + *O~D lf
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + zPe .
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' >\ W" 3.
FROM sysfiles 0dW1I|jR
WHERE name = @LogicalFileName vq}V0-
<
CREATE TABLE DummyTrans J']W7!p
(DummyColumn char (8000) not null) k>"I!&#g
DECLARE @Counter INT, gQ~4udla.
@StartTime DATETIME, Ad `IgZ
@TruncLog VARCHAR(255) -SQYr
SELECT @StartTime = GETDATE(), A:f+x|[
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' \] K-<&f
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Zh@\+1]
EXEC (@TruncLog) f+&yc'[
-- Wrap the log if necessary. 0W)_5f&
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired n !QjptQ
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ]+AI:
AND (@OriginalSize * 8 /1024) > @NewSize $1e@3mzM
BEGIN -- Outer loop. @,]v'l!u
SELECT @Counter = 0 <IYt*vlm
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 4.8,&{w<m
BEGIN -- update _~!,x.Dbp
INSERT DummyTrans VALUES ('Fill Log') 7Do)++t
DELETE DummyTrans \MU4"sXw
SELECT @Counter = @Counter + 1 PA E)3
END L<:ya
EXEC (@TruncLog) JsV#:
END S<TfvQ\,"@
SELECT 'Final Size of ' + db_name() + ' LOG is ' + DQSv'!KFO
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ]#nAld1cmy
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ]zO]*d=m
FROM sysfiles f]Vz !hM~
WHERE name = @LogicalFileName N|DY)W
DROP TABLE DummyTrans x{rt\OT
SET NOCOUNT OFF sb1/4u/W
8、说明:更改某个表 HwHI$IB
exec sp_changeobjectowner 'tablename','dbo' )~6974
9、存储更改全部表 MmX42;Pw
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch U+KbvkX wj
@OldOwner as NVARCHAR(128), MIgIt"M jz
@NewOwner as NVARCHAR(128) SNQ+ XtoO
AS
m ]\L1&
DECLARE @Name as NVARCHAR(128) &+\wYa,
DECLARE @Owner as NVARCHAR(128) ;(XSw%Y
H
DECLARE @OwnerName as NVARCHAR(128) SV.*Z|"^N
DECLARE curObject CURSOR FOR IAfYlS#<yD
select 'Name' = name, , Le_PJY)
'Owner' = user_name(uid) n}l Z
from sysobjects er53?z7zP.
where user_name(uid)=@OldOwner t/3veDh@
order by name HV}NT~
OPEN curObject Y !`H_Qo
FETCH NEXT FROM curObject INTO @Name, @Owner ;j$84o{
WHILE(@@FETCH_STATUS=0) *q^'%'
BEGIN ,"D1!0
if @Owner=@OldOwner G
5)?!
begin R{T4AZ@,'
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 6c2fqAF>i
exec sp_changeobjectowner @OwnerName, @NewOwner .m<-)Kx
end BjA|H
-- select @name,@NewOwner,@OldOwner !%Ak15o
FETCH NEXT FROM curObject INTO @Name, @Owner W?@ ;(k
END 7l?=$q>k"
close curObject E( TY%wO
deallocate curObject b`^$2RM&
GO ? f%@8%px
10、SQL SERVER中直接循环写入数据 (k[<>$hL*
declare @i int eN/Jb;W
set @i=1 IcA]<}0!"v
while @i<30 r@_;L>
begin o*<(,I%
insert into test (userid) values(@i) {vaq,2_w
set @i=@i+1 X3nwA#If1
end !l'Zar
小记存储过程中经常用到的本周,本月,本年函数 2-$R@
SVy
Dateadd(wk,datediff(wk,0,getdate()),-1) CSs3l
Dateadd(wk,datediff(wk,0,getdate()),6) 2W}RXqV<
Dateadd(mm,datediff(mm,0,getdate()),0) z.QW*rW9
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) Cnn,$R=/s
Dateadd(yy,datediff(yy,0,getdate()),0) o:?IT/>
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 5vS'Qhc
上面的SQL代码只是一个时间段 R8ZW1
Dateadd(wk,datediff(wk,0,getdate()),-1) pM>.z9
Dateadd(wk,datediff(wk,0,getdate()),6) +'[iyHBJ
就是表示本周时间段. 3mx7[Q
下面的SQL的条件部分,就是查询时间段在本周范围内的: blLX ncyD
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) m^TkFt<BM
而在存储过程中 ;$W|FpR2
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) +ux,cx.U"
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) (j2]:BVu