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。 ;TG<$4N
##qs{s^]
^`oyf{w@
一、基础 2$gOe^ &
1、说明:创建数据库 \>r<z46x
CREATE DATABASE database-name D$G:#z*
2、说明:删除数据库 2 1]87$
drop database dbname 8K0@*0
3、说明:备份sql server R3gg{hQ
--- 创建 备份数据的 device ^%k[YJtB=i
USE master @If ^5s;z
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' fr([g?F%D
--- 开始 备份 `f+l\'.s
BACKUP DATABASE pubs TO testBack y(0";\V
4、说明:创建新表 #&ZwQw
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) V.Ki$0>
根据已有的表创建新表: Uk|(VR9
A:create table tab_new like tab_old (使用旧表创建新表) 0*}%v:uN9
B:create table tab_new as select col1,col2... from tab_old definition only D "9Hv3
5、说明:删除新表 q\a'pp9d
drop table tabname {%Q&CQG_
6、说明:增加一个列 $d_%7 xx
Alter table tabname add column col type T`.RP&2/d
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 XhEd9>#
7、说明:添加主键: Alter table tabname add primary key(col) RkuPMs
Hw;
说明:删除主键: Alter table tabname drop primary key(col) /K<.$B8
8、说明:创建索引:create [unique] index idxname on tabname(col....) Y]gb`z$?
删除索引:drop index idxname UN6Du\)]d
注:索引是不可更改的,想更改必须删除重新建。 2dUVHu= +
9、说明:创建视图:create view viewname as select statement fd}
Ul
删除视图:drop view viewname O4i5fVy{
10、说明:几个简单的基本的sql语句 `cBV+00YS
选择:select * from table1 where 范围 Z:(yX0U,[
插入:insert into table1(field1,field2) values(value1,value2) bhWH
删除:delete from table1 where 范围 =UW!
7OzC
更新:update table1 set field1=value1 where 范围 46cd5SLK
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! pk0Cx
排序:select * from table1 order by field1,field2 [desc] lYq4f|5H}m
总数:select count as totalcount from table1 u!VAAX
求和:select sum(field1) as sumvalue from table1 WfDpeXdO
平均:select avg(field1) as avgvalue from table1 b;XUv4~V
最大:select max(field1) as maxvalue from table1 {2Jn#&Z29
最小:select min(field1) as minvalue from table1 UfUboxT
EgT2a
s]z-d!G
mOkf
11、说明:几个高级查询运算词 E1uyMh-dy
lSzLR~=Au
DZI:zsf;5Q
A: UNION 运算符 L| uoFG{
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。 Gcseq
B: EXCEPT 运算符 c{dge/2yb
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。 wtY*{m2
C: INTERSECT 运算符 9j;L-
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。 W+C@(}pt
注:使用运算词的几个查询结果行必须是一致的。 L-T3{I,3
12、说明:使用外连接 }Ra'`;D$
A、left outer join: 23AMrDF=N
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。 y(!YN7_A
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 ?!:$Z4G
B:right outer join: 9svn B@
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 >K2Md*[P3q
C:full outer join: DKG%z~R*
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 ktILKpHt"
eKq`t.*Ft
QKAo}1Pq
二、提升 5zqlK-$
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) Sf2pU!5n^
法一:select * into b from a where 1<>1 Gqz<;y
法二:select top 0 * into b from a ,(6U3W*bu
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) zdoJ+zRtK
insert into b(a, b, c) select d,e,f from b; Ie[8Iot?bn
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) 8$H_:*A?
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ,&1DKx
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. f<`is+"
4、说明:子查询(表名1:a 表名2:b) B|~tW21
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) =X0"!y"
5、说明:显示文章、提交人和最后回复时间 8KQ]3Z9p
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b y3]7^+k
6、说明:外连接查询(表名1:a 表名2:b) nnV(MB4z1
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c GtC bzNY
7、说明:在线视图查询(表名1:a ) t_-1sWeA!
select * from (SELECT a,b,c FROM a) T where t.a > 1; <F=U(WWn9
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 "t-u=aDl-.
select * from table1 where time between time1 and time2 f#s
/Ycp+
select a,b,c, from table1 where a not between 数值1 and 数值2 p@H3NX
9、说明:in 的使用方法 cBl
F
select * from table1 where a [not] in ('值1','值2','值4','值6') ^=H. .pr
10、说明:两张关联表,删除主表中已经在副表中没有的信息 1kG{z;9
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) vgc#IEx@
11、说明:四表联查问题: 8Rgvb3u
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 ..... k}5Sz
12、说明:日程安排提前五分钟提醒 SIBNU3;DL
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 f__r" N
13、说明:一条sql 语句搞定数据库分页 :
"|M
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 I.f)rMl+h
14、说明:前10条记录 [7Yfv
Xp
select top 10 * form table1 where 范围 zHI_U\"8D
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.) hP=^JH
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) E|(T(4;
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 }/ p>DMN
(select a from tableA ) except (select a from tableB) except (select a from tableC) Z'P>sV
17、说明:随机取出10条数据 hPs7mnSW
select top 10 * from tablename order by newid() :N \j@yJK
18、说明:随机选择记录 6;02_C]\o
select newid() HC4vet
19、说明:删除重复记录 %_rdO(
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) t:DZow
20、说明:列出数据库里所有的表名 Hh_Yd)
select name from sysobjects where type='U' Sn I-dXNF
21、说明:列出表里的所有的 e/pZLj]M
select name from syscolumns where id=object_id('TableName') y;)j
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。 uQwKnD?F+e
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 W| z
djb
显示结果: wA+QUN3#n
type vender pcs (]JZ1s|
电脑 A 1 t%
-"h|
电脑 A 1 FKTdQg|NZ
光盘 B 2 d|^cKLu
光盘 A 2 LL|uMe"Jb
手机 B 3 ]SqLF!S(=
手机 C 3 3{gD'y4j
23、说明:初始化表table1 o"^+ i#H!
TRUNCATE TABLE table1 YVzcV`4w(
24、说明:选择从10到15的记录 G~SgI>Q
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 5pJ)OX
Q.3oDq
5XK}8\
lzJ[ `i.
三、技巧 sFd"VRAV~E
1、1=1,1=2的使用,在SQL语句组合时用的较多 AqPE.mf
"where 1=1" 是表示选择全部 "where 1=2"全部不选, f}jo18z%
如: -Wp69DP6q
if @strWhere !='' r-27AJu
begin {`2R<O
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere f L @rv
end O}4(v #
else jwm2ZJW
begin t<_Jx<{2
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 0*G5Vd
end l>l)m-;O
我们可以直接写成 c,ccavv{I
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere `t0?PpUo
2、收缩数据库 ~VNN
--重建索引 L0v& m
DBCC REINDEX ?\_N*NEtK
DBCC INDEXDEFRAG Ix+===6
--收缩数据和日志 KmuE#Ia
DBCC SHRINKDB <SiD m-=E
DBCC SHRINKFILE 6XVr-ef
3、压缩数据库 deD%E-Ja
dbcc shrinkdatabase(dbname) HK@LA3
4、转移数据库给新用户以已存在用户权限 Q.5C$I
exec sp_change_users_login 'update_one','newname','oldname' PQla-
go rg Q6/3}qc
5、检查备份集 ' 0iXx
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' [kdt]+'+
6、修复数据库 $"P9I-\m
ALTER DATABASE [dvbbs] SET SINGLE_USER )Fc`rY
GO it=4cHT
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK b;wf7~a*
GO %bM^/7
ALTER DATABASE [dvbbs] SET MULTI_USER Yg 8AMi
GO @agW{%R:.
7、日志清除 44H#8kV
SET NOCOUNT ON X#l]%IrW!
DECLARE @LogicalFileName sysname, ^i3~i?\,P
@MaxMinutes INT, f/spJ<B).4
@NewSize INT DNsDEU
USE tablename -- 要操作的数据库名
z^s40707x
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 &Gp~)%
@MaxMinutes = 10, -- Limit on time allowed to wrap log. g8 (zvG;Y
@NewSize = 1 -- 你想设定的日志文件的大小(M) xkv2#"*v
-- Setup / initialize Da#|}m0>
DECLARE @OriginalSize int zWiMl.[
SELECT @OriginalSize = size \;0J6LBc
FROM sysfiles #qk}e4u
WHERE name = @LogicalFileName jM%qv
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 0qXkWGB
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + F$kLft[:
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' F...>%N$
FROM sysfiles DAs&4Y`
WHERE name = @LogicalFileName Pb0+z=L
CREATE TABLE DummyTrans 5 pNbO[
(DummyColumn char (8000) not null) NTRw:'
DECLARE @Counter INT, !!Tk'=t9"3
@StartTime DATETIME, &5&C
@TruncLog VARCHAR(255) 7g(,$5
SELECT @StartTime = GETDATE(), m?;aTSa
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' Lp\89tB>
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ]?P9M<0PM
EXEC (@TruncLog) 3}::"X
-- Wrap the log if necessary. .lMIJN&/
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired q2VQS1R`8
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) Rul Zh2C
AND (@OriginalSize * 8 /1024) > @NewSize .pNPC|XU
BEGIN -- Outer loop. ^H'zS3S
SELECT @Counter = 0 Wc4K?3 ZM
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) sY?pp
'}a
BEGIN -- update 1Yt;1k'
INSERT DummyTrans VALUES ('Fill Log') }{*((@GY}
DELETE DummyTrans E.v~<[g
SELECT @Counter = @Counter + 1 ;I'pC?!y
END 9wLV\>i[k
EXEC (@TruncLog) 4]$cf:
END =re1xR!E5
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ;EP]A3
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + H27J kZ&
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 0dhJ# [Y
FROM sysfiles DJ"O`qNV3
WHERE name = @LogicalFileName 2Up1
FFRx
DROP TABLE DummyTrans E?|"?R,,,
SET NOCOUNT OFF jyF0asb
8、说明:更改某个表 xw-x<7
exec sp_changeobjectowner 'tablename','dbo' %-@`|
9、存储更改全部表 7*5$=z4,1
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ^.Y"<oZSS
@OldOwner as NVARCHAR(128), >8;Co]::kx
@NewOwner as NVARCHAR(128) 2Mx9Kd'a
r
AS Yo:l@(
DECLARE @Name as NVARCHAR(128) ToIvyeFr
DECLARE @Owner as NVARCHAR(128) gP.Q_/V
DECLARE @OwnerName as NVARCHAR(128) q#B^yk|Y
DECLARE curObject CURSOR FOR }Jt( H
select 'Name' = name, )5P*O5kQ -
'Owner' = user_name(uid) c8mcJAc
from sysobjects _xign 3
where user_name(uid)=@OldOwner D/hQ{T
order by name R}4o{l6
OPEN curObject SymSAq0$F
FETCH NEXT FROM curObject INTO @Name, @Owner }x4,a6^
WHILE(@@FETCH_STATUS=0) yEt :g0Z\
BEGIN 2A@9jl s
if @Owner=@OldOwner wL,b.]
begin tYyva
set @OwnerName = @OldOwner + '.' + rtrim(@Name) le`&VdE^
exec sp_changeobjectowner @OwnerName, @NewOwner \sFdp!M}2
end +v%V1lf^~
-- select @name,@NewOwner,@OldOwner ABEC{3fWpu
FETCH NEXT FROM curObject INTO @Name, @Owner -CW&!oW
END :qy`!QPUm
close curObject y|b|_eE?{
deallocate curObject _)Uw-vhQiT
GO /zn|?Y[
10、SQL SERVER中直接循环写入数据 &NV[)6!
declare @i int %>'2E!%
set @i=1 _#9:cH*
while @i<30 *!UY;InanX
begin phSF.WC
insert into test (userid) values(@i) \/4ipU.
set @i=@i+1 dC@aQi6{6
end cs`/^2Vf"#
小记存储过程中经常用到的本周,本月,本年函数 c+AZ(6O?\
Dateadd(wk,datediff(wk,0,getdate()),-1) V
?3>hQtB
Dateadd(wk,datediff(wk,0,getdate()),6) w.J[3m/
Dateadd(mm,datediff(mm,0,getdate()),0) -yeQQ4b
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 5bFE;Y;
Dateadd(yy,datediff(yy,0,getdate()),0) zvL&V
.>
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) +Tc4+q!
上面的SQL代码只是一个时间段 zfL$z,zgf
Dateadd(wk,datediff(wk,0,getdate()),-1) (6z^m?t?
Dateadd(wk,datediff(wk,0,getdate()),6) 7P9n.
[
就是表示本周时间段. ?ECmPS1
下面的SQL的条件部分,就是查询时间段在本周范围内的: Mm-FdP
m
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) qAm$yfYs`
而在存储过程中 xBU\$ToC
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) g~.,-V}
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) `|wH=