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。 ^75pV%<%
C?bXrG\
i^~sn `o
一、基础 v)TUg0U=,
1、说明:创建数据库
$.=5e3
CREATE DATABASE database-name &C\=!r0j^
2、说明:删除数据库 ;%M2x5
drop database dbname [+yGDMLs
3、说明:备份sql server ,CN#co
--- 创建 备份数据的 device ?#x'_2
USE master N" 8*FiZ|
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' F1zT )wW
--- 开始 备份 3@%BA(M
BACKUP DATABASE pubs TO testBack pFG]IM7o/u
4、说明:创建新表 6
bYC
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) uF.Q " ,<
根据已有的表创建新表: elNB7%Y/
A:create table tab_new like tab_old (使用旧表创建新表) &`-_)~5]
B:create table tab_new as select col1,col2... from tab_old definition only 3{6ps : w
5、说明:删除新表 o$*bm6o
drop table tabname Q=dw 6
6、说明:增加一个列 oA5<[&~<
Alter table tabname add column col type -wJ
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。 ccIDMJ=2
7、说明:添加主键: Alter table tabname add primary key(col) 6hR^qdHg
说明:删除主键: Alter table tabname drop primary key(col) '3IkPy1Uz
8、说明:创建索引:create [unique] index idxname on tabname(col....) oD Q9.t
删除索引:drop index idxname Zjw!In|vC
注:索引是不可更改的,想更改必须删除重新建。 02;f2;I
9、说明:创建视图:create view viewname as select statement {(8U8f<'=y
删除视图:drop view viewname YWybPD4\(
10、说明:几个简单的基本的sql语句 gF$1wV]e
选择:select * from table1 where 范围 !k4 }v'=
插入:insert into table1(field1,field2) values(value1,value2) AEi WL.*.
删除:delete from table1 where 范围 i/l!Cr2
更新:update table1 set field1=value1 where 范围 Pm;x]Aj
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! -9hp+0 <
排序:select * from table1 order by field1,field2 [desc] oNh68ON:c
总数:select count as totalcount from table1 7uWJ6Wk
求和:select sum(field1) as sumvalue from table1 `M towXj
平均:select avg(field1) as avgvalue from table1 JS }_q1H
最大:select max(field1) as maxvalue from table1 @2)t#~Wc4h
最小:select min(field1) as minvalue from table1 i7Y
s_8A"9
BXagSenc
<>ZBW9
o6`Y7,]
11、说明:几个高级查询运算词 3RBpbTNWp
r3*+8D~a_
$w 5#2Za
A: UNION 运算符 0[_O+u
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 9/@FADh
B: EXCEPT 运算符 ~Rx~g
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 BYhmJC|
C: INTERSECT 运算符 PmuEL@'^ U
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 N`
@W%
注:使用运算词的几个查询结果行必须是一致的。 =*@MQ
12、说明:使用外连接 4f_ZY5=
A、left outer join: fU\k?'x_
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 fzq'S]+
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 5WrIg(l
B:right outer join: O6*'gnke
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 G~b`O20N
C:full outer join: yf0vR%,\
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 5i}CzA96
cKvAR5|
\;A50U|r
二、提升 ~z-?rW
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) bn^mL~
法一:select * into b from a where 1<>1 9b"}CEw
法二:select top 0 * into b from a 60Xl.
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) [qO5~E`;
insert into b(a, b, c) select d,e,f from b; 2ID*U d*
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) y@2vY[)3s
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 #U\&i`
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Huc3|~9
4、说明:子查询(表名1:a 表名2:b) _RA{SO
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) j3sz*:
5、说明:显示文章、提交人和最后回复时间 >x|A7iWn{,
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b r_!{!i3B
6、说明:外连接查询(表名1:a 表名2:b) LLXg
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Zpn*XG
7、说明:在线视图查询(表名1:a ) Y&1!Z*OL;
select * from (SELECT a,b,c FROM a) T where t.a > 1; @'k,\$ /
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 Q{ |+3!!'
select * from table1 where time between time1 and time2 -$sl!%HO%
select a,b,c, from table1 where a not between 数值1 and 数值2 K#m\qitb
9、说明:in 的使用方法 iMOPD}`IX
select * from table1 where a [not] in ('值1','值2','值4','值6') bn<I#ZH2
10、说明:两张关联表,删除主表中已经在副表中没有的信息 xr7-[)3Q$
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 8M".o n
11、说明:四表联查问题: ue^?/{OuT
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 ..... 42b=z//;
12、说明:日程安排提前五分钟提醒
t?Njw7
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 *Dd(+NI
13、说明:一条sql 语句搞定数据库分页
]*kP>
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 pUCEYR
14、说明:前10条记录 ^^t]vojX
select top 10 * form table1 where 范围 82^
z-t{
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.) EA%#/n
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 'AAF/ 9
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 EDPI*@>
(select a from tableA ) except (select a from tableB) except (select a from tableC) x0AqhT5}
17、说明:随机取出10条数据 O|^6UH
select top 10 * from tablename order by newid() FEm1^X#]
18、说明:随机选择记录 'aSZ!R
select newid() oJ4mxi@|#
19、说明:删除重复记录 )|59FOWg
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 5W:Gl?$S}
20、说明:列出数据库里所有的表名 sTYuwna~
select name from sysobjects where type='U' U:etcnb4w>
21、说明:列出表里的所有的 dZ;~b(CA
select name from syscolumns where id=object_id('TableName') #V(Hk )
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 dH2j*G Ij
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type //'xR8Z
显示结果: ATXx?
b8h
type vender pcs ?=|)n%
电脑 A 1 fxtYo,;$
电脑 A 1 @'NaA SB
光盘 B 2 n'x`oI)-
光盘 A 2 XSHwE)m
手机 B 3 lhIr]'?l
手机 C 3 c!(~BH3p
23、说明:初始化表table1 {8>_,z^P)
TRUNCATE TABLE table1 iBPdCp%]`
24、说明:选择从10到15的记录 bCY^.S-
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc q)z1</B-
x9{Sl[2&
HPd+Bd
Ekg N6S`}
三、技巧 +^]PBMM1w
1、1=1,1=2的使用,在SQL语句组合时用的较多 U(Hq4D
"where 1=1" 是表示选择全部 "where 1=2"全部不选, }~Kyw7?
如: wzLiVe-
if @strWhere !='' CpP$HrQ
begin B 3,ig9
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 4o)\DB?!
end ?G%, k
LJJ
else E%J7jA4
begin {ZBb.$}RC
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' yW6[Fpw
end a s<q
我们可以直接写成 Lu#@~
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere /KJx n6
2、收缩数据库 MR l*rK
--重建索引 /S=;DxZ,r
DBCC REINDEX 2}xFv2X
DBCC INDEXDEFRAG |Z^c#R
--收缩数据和日志 )lngef
/D_
DBCC SHRINKDB \PtC
DBCC SHRINKFILE 'mY,>#sT
3、压缩数据库 @u'27c_<d3
dbcc shrinkdatabase(dbname) /iJcy:J
4、转移数据库给新用户以已存在用户权限 37M[9m|D*
exec sp_change_users_login 'update_one','newname','oldname' M@LaD 5
go N-?|]4e/
5、检查备份集 )1tnZ=&
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 3K'o&>}L
6、修复数据库 me}Gb a
ALTER DATABASE [dvbbs] SET SINGLE_USER dO4U9{+
GO c_8 mQ
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ;HLMU36q
GO ^2?O+ =,F
ALTER DATABASE [dvbbs] SET MULTI_USER w\8rh\Mvh
GO Y[8co<p
7、日志清除 efAahH
SET NOCOUNT ON }RP 9%n^
DECLARE @LogicalFileName sysname, n-| i
@MaxMinutes INT, 8Q)mmkI\=
@NewSize INT |Nx!g fU
USE tablename -- 要操作的数据库名 K&a]pL6D
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 {]_{BcK+
@MaxMinutes = 10, -- Limit on time allowed to wrap log. *mhw5Z=!
@NewSize = 1 -- 你想设定的日志文件的大小(M) Uub%s`O
-- Setup / initialize gJ[q
{b
DECLARE @OriginalSize int &fNE9peQFa
SELECT @OriginalSize = size MFdFZkpiV
FROM sysfiles YvP"W/5
WHERE name = @LogicalFileName <T2~xn
SELECT 'Original Size of ' + db_name() + ' LOG is ' + R7;rBEt8
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ,;ruH^
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' uRq#pYn@
FROM sysfiles Er+3S@sfq,
WHERE name = @LogicalFileName
s?\9i6
CREATE TABLE DummyTrans fOjt` ~ToI
(DummyColumn char (8000) not null) d\<aJOi+-
DECLARE @Counter INT, #/sE{jm
@StartTime DATETIME, 02c.;ka3
@TruncLog VARCHAR(255) [Jh))DIx
SELECT @StartTime = GETDATE(), `R=_t]ie
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' Vi-!E
DBCC SHRINKFILE (@LogicalFileName, @NewSize) AYQh=$)(
EXEC (@TruncLog) ujHzG}2z
-- Wrap the log if necessary. ZtK%b+MBP
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired .gsu_N_v
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) KL\=:iWA
AND (@OriginalSize * 8 /1024) > @NewSize "E[*rnsLN
BEGIN -- Outer loop. n YMf[kW
SELECT @Counter = 0 Cq;K,B9
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ' ^L
BEGIN -- update hw.demD
INSERT DummyTrans VALUES ('Fill Log') E?5B>Jer#
DELETE DummyTrans ;NVTn<Uj
SELECT @Counter = @Counter + 1 wTAEJ{p
END f!kdcr=/"
EXEC (@TruncLog) iqKfMoy5
END {^O/MMB\\%
SELECT 'Final Size of ' + db_name() + ' LOG is ' + SVEA
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + }PD(kk6fX
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' w0%ex#lkm
FROM sysfiles ]~x/8%e76
WHERE name = @LogicalFileName :bF2b..XOu
DROP TABLE DummyTrans %|6Q7'@p
SET NOCOUNT OFF 7z0uj
8、说明:更改某个表 >U
Ich
exec sp_changeobjectowner 'tablename','dbo' g:6}zHK
9、存储更改全部表 )^2jsy
-/
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch g<0%-p
@OldOwner as NVARCHAR(128), LFM5W&?
@NewOwner as NVARCHAR(128) )^@V*$D
AS %Bu n@
DECLARE @Name as NVARCHAR(128) [-94=|S @
DECLARE @Owner as NVARCHAR(128) iW%0pLn
DECLARE @OwnerName as NVARCHAR(128) O
NzdCgY
DECLARE curObject CURSOR FOR kk./-G
select 'Name' = name, X!HSS/'
'Owner' = user_name(uid) ^>}[[:( 6/
from sysobjects [67f; ?b
where user_name(uid)=@OldOwner d1_*!LW$
order by name JRs[%w`kD
OPEN curObject ;? QAPTz
FETCH NEXT FROM curObject INTO @Name, @Owner $,v+i
-
WHILE(@@FETCH_STATUS=0) 91Sb=9
BEGIN <u%e*
if @Owner=@OldOwner .8xacVyK2
begin Ox1QP2t6Y
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 8n
p>#V
exec sp_changeobjectowner @OwnerName, @NewOwner FrM~6A_
end cx%9UK*c
-- select @name,@NewOwner,@OldOwner H4",r5qw:
FETCH NEXT FROM curObject INTO @Name, @Owner 6#63D>OWp
END 4U1fPyt
close curObject u\Q**m2XP
deallocate curObject PsT v\!
GO bH]!~[
10、SQL SERVER中直接循环写入数据 C^v- &*v
declare @i int _;RD-kv
set @i=1 N28?JQha
while @i<30 `D4'`Or-U
begin mP+yjRw
insert into test (userid) values(@i) d'nuk#r
set @i=@i+1 n&&U9sf?
end kF~e3A7C
小记存储过程中经常用到的本周,本月,本年函数 :rc[j@|pH
Dateadd(wk,datediff(wk,0,getdate()),-1) ~a,'
Dateadd(wk,datediff(wk,0,getdate()),6) ]* Ki7h|B
Dateadd(mm,datediff(mm,0,getdate()),0) m&c(N
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) Olh-(u:9+O
Dateadd(yy,datediff(yy,0,getdate()),0) AsF`A"Cdw<
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) iz5wUyeg
上面的SQL代码只是一个时间段 xJ5!`#=
Dateadd(wk,datediff(wk,0,getdate()),-1) k(Xv&Zn
Dateadd(wk,datediff(wk,0,getdate()),6) nezbmpL4
就是表示本周时间段. QRa6*AYm
下面的SQL的条件部分,就是查询时间段在本周范围内的: AQU: 0
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) N>\?Aeh
而在存储过程中 {/!"}{G1e
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) w:(7fu=
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ExU|EN-