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。 'A)r)z{X
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一、基础 MFqM6_
1、说明:创建数据库 $#LR4 [Fq
CREATE DATABASE database-name *r|)@K|
2、说明:删除数据库 f>kW\uC
drop database dbname f.Feo
3、说明:备份sql server \Zbi`;m?
--- 创建 备份数据的 device vAH `tPi>
USE master y>jP]LR4
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 9}*<8%PSt,
--- 开始 备份 lVR
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BACKUP DATABASE pubs TO testBack X$(Dem
4、说明:创建新表 'BmLR{[2L
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) .^aqzA=]
根据已有的表创建新表: N "Mw1R4
A:create table tab_new like tab_old (使用旧表创建新表) jt,dr3|/n
B:create table tab_new as select col1,col2... from tab_old definition only _DAj$$ Ru4
5、说明:删除新表 (yxHXO9N
drop table tabname 7,:$, bL
6、说明:增加一个列 AttS?TZr
Alter table tabname add column col type d&apu{
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 m\xlSNW'q
7、说明:添加主键: Alter table tabname add primary key(col) Z(0sMOaX
说明:删除主键: Alter table tabname drop primary key(col) T=D|jt
8、说明:创建索引:create [unique] index idxname on tabname(col....) nBo?r}t4
删除索引:drop index idxname 3sF^6<E
注:索引是不可更改的,想更改必须删除重新建。 O[RivHCY
9、说明:创建视图:create view viewname as select statement [t }\8^y
删除视图:drop view viewname IyJHKDFk
10、说明:几个简单的基本的sql语句 N_^s;Qj
选择:select * from table1 where 范围 *%;+3SV
插入:insert into table1(field1,field2) values(value1,value2) .lE7v -e
删除:delete from table1 where 范围 /@qnEP%
更新:update table1 set field1=value1 where 范围 SoPiEq
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! H\!p%Y
排序:select * from table1 order by field1,field2 [desc] P<s0f:".
总数:select count as totalcount from table1
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求和:select sum(field1) as sumvalue from table1 RP|/rd]-k
平均:select avg(field1) as avgvalue from table1 l Taw6;
最大:select max(field1) as maxvalue from table1 B;=-h(E}vJ
最小:select min(field1) as minvalue from table1 f9FEH7S68
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11、说明:几个高级查询运算词 ;2\+O"}4H
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A: UNION 运算符 x_VD9
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 {$H-7-O$
B: EXCEPT 运算符 o +KDK{MD
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。 ;FfDi*S7
C: INTERSECT 运算符 {2,vxGi
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。 p;0p!~F=49
注:使用运算词的几个查询结果行必须是一致的。 X" m0||
12、说明:使用外连接 jqv"8S5
A、left outer join: b;k3B7<
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。 t]14bf$*Q
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c YkuFt>U9,
B:right outer join: K~6,xZlDWM
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 rK@XC +`S
C:full outer join: F :p9y_W
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 lC8Z@wkjO
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二、提升 qSA]61U&
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ;U)xZ _Ew~
法一:select * into b from a where 1<>1 *l{GD1ZDk
法二:select top 0 * into b from a <reALC
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 3LW_qX
insert into b(a, b, c) select d,e,f from b; 0(|Yy/Yq
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) BL[N
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 RzOcz=A}
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. dtx3;d<NsJ
4、说明:子查询(表名1:a 表名2:b) +S6(Fvp
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) R(AS$<p{!>
5、说明:显示文章、提交人和最后回复时间 J5Ovj,[EZ
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b +oev NM
6、说明:外连接查询(表名1:a 表名2:b) s~'"&0Gz
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 'B\7P*L"p
7、说明:在线视图查询(表名1:a ) Ek6z[G`
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select * from (SELECT a,b,c FROM a) T where t.a > 1; NpLZ
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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 7z;X@+O}s
select * from table1 where time between time1 and time2 c4V%>A
select a,b,c, from table1 where a not between 数值1 and 数值2 xQ,My
9、说明:in 的使用方法 9T#${NK
select * from table1 where a [not] in ('值1','值2','值4','值6') lW|`8ykp
10、说明:两张关联表,删除主表中已经在副表中没有的信息 )lZoXt_3
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) rt0_[i
11、说明:四表联查问题: H! P$p-*.
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 ..... SceK$
12、说明:日程安排提前五分钟提醒 363KU@`
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 2!Qg1hM
13、说明:一条sql 语句搞定数据库分页 K1$
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 lG5KZ[/Or
14、说明:前10条记录 ")YD~ZA%)
select top 10 * form table1 where 范围 i_e%HG
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.) SA?lDRF
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) J'C9}7G
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 $1 t
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(select a from tableA ) except (select a from tableB) except (select a from tableC) >@)p*y.K
17、说明:随机取出10条数据 %<0'xJ%%Q
select top 10 * from tablename order by newid() q ;"/i*+3
18、说明:随机选择记录 UZpQ%~/
select newid() _#K?yP?
19、说明:删除重复记录 AO238RC!:
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) [vqf hpz
20、说明:列出数据库里所有的表名 I(H9-!&
select name from sysobjects where type='U' $5:I~-mx
21、说明:列出表里的所有的 rf+Z0C0WYi
select name from syscolumns where id=object_id('TableName') Ae\:{[c_D
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 B$M4f7
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 lVCnu>8
显示结果: IIN,Da;hD
type vender pcs Kr?<7vMT5
电脑 A 1 }9kn;rb$g
电脑 A 1 K@%gvLa\
光盘 B 2 8<Pi}RH
光盘 A 2 EW`3$J;
手机 B 3 _Q 'f^Kj
手机 C 3 7g$*K0m`
23、说明:初始化表table1 h=Q2
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TRUNCATE TABLE table1 MOPHu
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24、说明:选择从10到15的记录 !mmSF1f
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 6"?#E[ #[
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三、技巧 #"8'y
1、1=1,1=2的使用,在SQL语句组合时用的较多 >;l rH&
"where 1=1" 是表示选择全部 "where 1=2"全部不选, EeHghq
如: 9oIfSr,y
if @strWhere !='' F"cZ$TL]
begin "[-W(=
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere p( )LQT!
end
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else 6VS_L@
begin Khl0 ~
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' yY{
end *2fJdY
我们可以直接写成 );h
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ]"^p}:
2、收缩数据库 R#i`H(N
--重建索引 byTHSRt
DBCC REINDEX 8)MWC:
DBCC INDEXDEFRAG nN^lY=3
--收缩数据和日志 Yg}b%u,Q
DBCC SHRINKDB _[Sh`4`r
DBCC SHRINKFILE #
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3、压缩数据库 6oFA=CjU{
dbcc shrinkdatabase(dbname) R<vbhB/lU
4、转移数据库给新用户以已存在用户权限 %eh.@8GL`
exec sp_change_users_login 'update_one','newname','oldname' y2mSPLw
go 3[m2F O,Z
5、检查备份集 $Yp.BE<}
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' yu@Pd3
6、修复数据库 bR1Q77<G\
ALTER DATABASE [dvbbs] SET SINGLE_USER kem(U{m
GO m.\JO
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK o
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GO ms\\R@R
ALTER DATABASE [dvbbs] SET MULTI_USER N7KG_o%
GO B#}EYY
7、日志清除 uHRxV"@}[1
SET NOCOUNT ON <r(D\rmD
DECLARE @LogicalFileName sysname, UI'fzlB
@MaxMinutes INT, 1*'gaa&y
@NewSize INT rQ6>*0xL_
USE tablename -- 要操作的数据库名 c4r9k-w0E
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 !qHB?]
@MaxMinutes = 10, -- Limit on time allowed to wrap log. aR'~=t&;z1
@NewSize = 1 -- 你想设定的日志文件的大小(M) i2;,\FI@t%
-- Setup / initialize 86!$<!I
DECLARE @OriginalSize int Zz]/4 4t
SELECT @OriginalSize = size xP;>p|
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FROM sysfiles 0%Y}CDn_
WHERE name = @LogicalFileName Y"^.6
SELECT 'Original Size of ' + db_name() + ' LOG is ' + _meW9)B
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + c/:k|x
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' d2)]6)z6
FROM sysfiles cM4{ e^
WHERE name = @LogicalFileName }n#$p{e$i
CREATE TABLE DummyTrans feeHXKD|
(DummyColumn char (8000) not null) +x/vZXtOK
DECLARE @Counter INT, Iz;^D!
@StartTime DATETIME, <OJqeUo+*\
@TruncLog VARCHAR(255) M'oZK
SELECT @StartTime = GETDATE(), =vriraV"
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 6+"gk(
DBCC SHRINKFILE (@LogicalFileName, @NewSize) -V[!qI
EXEC (@TruncLog) ?YDMl
-- Wrap the log if necessary. NR-<2
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired wlslG^^(!
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) =UWW(^M#[:
AND (@OriginalSize * 8 /1024) > @NewSize rY1jC\
BEGIN -- Outer loop. ,^<39ng
SELECT @Counter = 0 3H4T*&9;n
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) B(6*U~Kn%
BEGIN -- update -7o-d-d F
INSERT DummyTrans VALUES ('Fill Log') vq-;wdq?2
DELETE DummyTrans )7Qp9Fxo
SELECT @Counter = @Counter + 1 &%k_BdlkQ
END PL!dkaD^y>
EXEC (@TruncLog) 0dI7{o;<|
END SJi;_bVf
SELECT 'Final Size of ' + db_name() + ' LOG is ' + lH@goh
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 7s2*VKr
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' /^I!)|At
FROM sysfiles TV0Y{x*~iH
WHERE name = @LogicalFileName gp
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DROP TABLE DummyTrans *"6A>:rQs
SET NOCOUNT OFF JS<w43/j
8、说明:更改某个表 q./jYe
exec sp_changeobjectowner 'tablename','dbo' w vI
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9、存储更改全部表 F&3 :]1
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch HzuG- V
@OldOwner as NVARCHAR(128), 1|>bG#|
@NewOwner as NVARCHAR(128) 6x/o j`_[
AS +bb-uoZf
DECLARE @Name as NVARCHAR(128) [(.lfa P
DECLARE @Owner as NVARCHAR(128) jMX|1b
DECLARE @OwnerName as NVARCHAR(128) w_LkS/
DECLARE curObject CURSOR FOR 1:./f|m
select 'Name' = name, 3vQVk
'Owner' = user_name(uid) r&:yZN
from sysobjects 7qWa>fX
where user_name(uid)=@OldOwner AP4s_X+=
order by name -$@'@U
OPEN curObject <A`SC;k\u
FETCH NEXT FROM curObject INTO @Name, @Owner 1}p:]/;
WHILE(@@FETCH_STATUS=0) &XXr5ne~C
BEGIN RmOkb~
if @Owner=@OldOwner nf:wJ-;*
begin sqRvnCD!
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ST4[d'|j
exec sp_changeobjectowner @OwnerName, @NewOwner q%)."10}]
end vAOThj)
-- select @name,@NewOwner,@OldOwner }wJH@'0+
FETCH NEXT FROM curObject INTO @Name, @Owner `>lY$EBG@[
END qzSm]l?z
close curObject zU4*FXt
deallocate curObject 4CS$%Cu\?w
GO 8M BY3F
10、SQL SERVER中直接循环写入数据 9PaV*S(\TR
declare @i int %.fwNS
set @i=1 Fa{[kJ8z
while @i<30 7x*C`
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begin DV*e.Y>
insert into test (userid) values(@i) U0N6\+
set @i=@i+1 Z]Cd> u
end ogV v 8Xb
小记存储过程中经常用到的本周,本月,本年函数 >yLdrf
Dateadd(wk,datediff(wk,0,getdate()),-1) 7$*x&We
Dateadd(wk,datediff(wk,0,getdate()),6) &F'n
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Dateadd(mm,datediff(mm,0,getdate()),0) Ksk[sf?J&
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) "od2i\
Dateadd(yy,datediff(yy,0,getdate()),0) tvUC d}
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) lj+&3<E
上面的SQL代码只是一个时间段 iWkC:fQz
Dateadd(wk,datediff(wk,0,getdate()),-1) ITz+O=I4R]
Dateadd(wk,datediff(wk,0,getdate()),6) &,\my-4c>
就是表示本周时间段. i7&ay\+@
下面的SQL的条件部分,就是查询时间段在本周范围内的: @jZ1WHS_a
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) bJw{ U.
而在存储过程中
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) hdH3Jb_hl(
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) _Y)Wi[