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。 O `*}N1No[
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一、基础 zI&oZH^vn
1、说明:创建数据库 E;k'bz
CREATE DATABASE database-name }yUZ(k#
2、说明:删除数据库 fF;-d2mF
drop database dbname 0Y{A
3、说明:备份sql server iJU]|t
--- 创建 备份数据的 device moh7:g
USE master (Ori].{C.J
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' /.P*%'g
--- 开始 备份 '(;`t1V8k
BACKUP DATABASE pubs TO testBack 3#W>
4、说明:创建新表 Ve<l7U;
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) N\rbnr
根据已有的表创建新表: 5EM(3eY ^q
A:create table tab_new like tab_old (使用旧表创建新表) 2}K7(y!?u
B:create table tab_new as select col1,col2... from tab_old definition only awGI|d
5、说明:删除新表 FgLV>#)-
drop table tabname &;|/I`+
6、说明:增加一个列 Jc/*w
Alter table tabname add column col type PE0A `
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。 Ng2qu!F7
7、说明:添加主键: Alter table tabname add primary key(col) 3 cu`U`
说明:删除主键: Alter table tabname drop primary key(col) ,..&j+m
8、说明:创建索引:create [unique] index idxname on tabname(col....)
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删除索引:drop index idxname >2TDYB|;
注:索引是不可更改的,想更改必须删除重新建。 `$7.(.#s
9、说明:创建视图:create view viewname as select statement 9ELLJ@oNC
删除视图:drop view viewname 4u0=/pfi[
10、说明:几个简单的基本的sql语句 [td)v,
选择:select * from table1 where 范围 Y:XE4v/)@L
插入:insert into table1(field1,field2) values(value1,value2) h${+{1](6
删除:delete from table1 where 范围 ,E<(K8
更新:update table1 set field1=value1 where 范围 N[:;f^bH49
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! CNwIM6t
排序:select * from table1 order by field1,field2 [desc] (
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总数:select count as totalcount from table1 R5(<:]
求和:select sum(field1) as sumvalue from table1 Kf/1;:^
平均:select avg(field1) as avgvalue from table1 /I(IT=kp
最大:select max(field1) as maxvalue from table1 LB1LQ0M
最小:select min(field1) as minvalue from table1 W1fEUVj
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11、说明:几个高级查询运算词 }rRf4te
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A: UNION 运算符 $dIu${lu
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。 c6 VfFt6p
B: EXCEPT 运算符 K Rs
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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。 ;6P#V`u
C: INTERSECT 运算符 ra2sYH1wr
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。 9.)*z-f$
注:使用运算词的几个查询结果行必须是一致的。 Er509zZ,[
12、说明:使用外连接 5n{J}0C
A、left outer join: Y>W$n9d&G2
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 iZm#
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SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c T%zCAfx m
B:right outer join: 5P'o+Vwz
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 ;r'y/Y'?
C:full outer join: lOB*M!8
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 Av6=q=D
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二、提升 j=c=Pe"?u
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) NX.%Rj*
法一:select * into b from a where 1<>1 :buH\LB*P
法二:select top 0 * into b from a \A
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) cC@.&
insert into b(a, b, c) select d,e,f from b; {P/ sxh:e
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) yR}PC/>
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 v_=xN^R
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. dRC
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4、说明:子查询(表名1:a 表名2:b) bT93R8yp
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) -QPM$
5、说明:显示文章、提交人和最后回复时间 xwvg@
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b d6RO2^
6、说明:外连接查询(表名1:a 表名2:b) 4sJM!9eb[
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c <=O/_Iu(
7、说明:在线视图查询(表名1:a ) iB-h3/
select * from (SELECT a,b,c FROM a) T where t.a > 1; 0'm$hU}
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 lSW6\jX
select * from table1 where time between time1 and time2 uO]^vP]fT
select a,b,c, from table1 where a not between 数值1 and 数值2 '2LK(uaU
9、说明:in 的使用方法 HgVPyo
select * from table1 where a [not] in ('值1','值2','值4','值6') /xS4>@hn
10、说明:两张关联表,删除主表中已经在副表中没有的信息 (g(.gN]
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) l rRRRR
11、说明:四表联查问题: vH[G#A~4
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... :2v^pg|
12、说明:日程安排提前五分钟提醒 yZHh@W4v
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 'J[n}r
13、说明:一条sql 语句搞定数据库分页 0XgJCvMcB
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 ;pH&YBY
14、说明:前10条记录 *HC[LM
select top 10 * form table1 where 范围 40?xu#"
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) C4,;l^?=%
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) D6Q6yNE
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 27"M]17)
(select a from tableA ) except (select a from tableB) except (select a from tableC) pYxdE|2j
17、说明:随机取出10条数据 *- S/{
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select top 10 * from tablename order by newid()
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18、说明:随机选择记录 \jR('5DcB
select newid() BI|BfO%F$j
19、说明:删除重复记录 'L k&iph
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Q|$?d4La8
20、说明:列出数据库里所有的表名 .,vF%pQ
select name from sysobjects where type='U' - WEEnwZ
21、说明:列出表里的所有的 <i1.W!%
select name from syscolumns where id=object_id('TableName') isF
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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。 $E >)
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type eV"Za.a.
显示结果:
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type vender pcs arQEi
电脑 A 1 P&g.%8b~84
电脑 A 1 6he (v
光盘 B 2 QIb4ghm,
光盘 A 2 NA/hs/ '
手机 B 3 ,ve$bSp
手机 C 3 d*cAm$
23、说明:初始化表table1 USDqh437
TRUNCATE TABLE table1 cUDo}Yu
24、说明:选择从10到15的记录 3;E,B7,mQ
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc kv8
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三、技巧 WGC'k
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1、1=1,1=2的使用,在SQL语句组合时用的较多 C)H1<Br7
"where 1=1" 是表示选择全部 "where 1=2"全部不选, f8AgTw,K8
如: h ycdk1SN
if @strWhere !='' ajJ+Jn\
begin G&DL)ePu]m
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere jb'AOs
end ohW
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else 3[ T<pAZ
begin D,( "3zx
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' OtsW>L@ O(
end U%qE=u-
我们可以直接写成 ^?Y x{r~9
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ?*K{1Ghf
2、收缩数据库 <q<kqy5s-R
--重建索引 <<iwJ
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DBCC REINDEX @TqqF:c7
DBCC INDEXDEFRAG E4;@P']`
--收缩数据和日志 $KAOJc4<
DBCC SHRINKDB B{dR/q3;@
DBCC SHRINKFILE >`S $(f
3、压缩数据库 C\RJ){dk
dbcc shrinkdatabase(dbname) um}%<Cy[
4、转移数据库给新用户以已存在用户权限 g q`S`
exec sp_change_users_login 'update_one','newname','oldname' wBaIN]Y,
go KJQW ))%e
5、检查备份集 7#G8qh<
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' XqxmvN
6、修复数据库 `(Eiu$h6V-
ALTER DATABASE [dvbbs] SET SINGLE_USER kbcqUE
GO L &nqlH@+~
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK BK/~2u
GO %c`P`~sp
ALTER DATABASE [dvbbs] SET MULTI_USER s/cclFji]
GO Rg,]du u?
7、日志清除 y2=`NG=
SET NOCOUNT ON \]7i-[
DECLARE @LogicalFileName sysname, u.~`/O
@MaxMinutes INT, 7{fOo%(7
@NewSize INT O_bgrXg6x
USE tablename -- 要操作的数据库名 uNoP8U%*
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 SAUfA5|e
@MaxMinutes = 10, -- Limit on time allowed to wrap log. EH2a
@NewSize = 1 -- 你想设定的日志文件的大小(M) TTQ(\l4
-- Setup / initialize =|Vm69
DECLARE @OriginalSize int 6U!zc]>
SELECT @OriginalSize = size !L|PDGD
FROM sysfiles 873'=m&
WHERE name = @LogicalFileName NBaXfWh
SELECT 'Original Size of ' + db_name() + ' LOG is ' + x } X1
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + +`_Km5=
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' wLW[Vur[
FROM sysfiles hF4gz*Q
WHERE name = @LogicalFileName 'qt+.vd
CREATE TABLE DummyTrans u
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(DummyColumn char (8000) not null) Hi5}s
DECLARE @Counter INT, j7u\.xu9
@StartTime DATETIME, 1nAAs;`'
@TruncLog VARCHAR(255) AhauNS^"{R
SELECT @StartTime = GETDATE(), _ giZ'&l!
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' o+F]80CH
DBCC SHRINKFILE (@LogicalFileName, @NewSize) K2gg"#ft?
EXEC (@TruncLog) PYPDK*Ie
-- Wrap the log if necessary. iM'rl0
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired _1EWmHZ?
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) cE SSSH!m
AND (@OriginalSize * 8 /1024) > @NewSize SGK=WLGM8
BEGIN -- Outer loop. g]a5%8*{
SELECT @Counter = 0 @b2JR^
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) m:4Ec>?e
BEGIN -- update s>+,u7EV
INSERT DummyTrans VALUES ('Fill Log') ]%I}hjJ
DELETE DummyTrans (Ymj
SELECT @Counter = @Counter + 1 %hO/2u
END }
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EXEC (@TruncLog) 8H<:?D/tH
END l$mfsm|{:
SELECT 'Final Size of ' + db_name() + ' LOG is ' + )cUFb:D*"
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + H}}g\|r&
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' w]Byl3}Gt
FROM sysfiles 4y$tp18
WHERE name = @LogicalFileName
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DROP TABLE DummyTrans 8O='Q-&8
SET NOCOUNT OFF ^9wQl!e
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8、说明:更改某个表 e/*T,ZJ
exec sp_changeobjectowner 'tablename','dbo' :3$$PdZ
9、存储更改全部表 r)Dln5F
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch a3?D@@Qnw
@OldOwner as NVARCHAR(128), n$z+g>~N
@NewOwner as NVARCHAR(128) 1w|C+m/(
AS Cg 4l*"_
DECLARE @Name as NVARCHAR(128) [l%6wIP&{
DECLARE @Owner as NVARCHAR(128) $CgR~D2G
DECLARE @OwnerName as NVARCHAR(128) +;*dFL
DECLARE curObject CURSOR FOR ehe;<A
select 'Name' = name, V \4zK$]
'Owner' = user_name(uid) R-\a3q
from sysobjects [n!5!/g>j
where user_name(uid)=@OldOwner x.ZW%P1
order by name ,y%4QvG7a
OPEN curObject b!hs|emo;
FETCH NEXT FROM curObject INTO @Name, @Owner zFpM\{`[g
WHILE(@@FETCH_STATUS=0) m(6SiV=D9
BEGIN .{}=!>U2
if @Owner=@OldOwner (|kcSnF0
begin 2$OI(7b=
set @OwnerName = @OldOwner + '.' + rtrim(@Name) We51s^(
exec sp_changeobjectowner @OwnerName, @NewOwner |MEu"pY)
end P9/Bc^5'
-- select @name,@NewOwner,@OldOwner 'L1=:g.\i
FETCH NEXT FROM curObject INTO @Name, @Owner -o`Eka!ELz
END aUVJ\;V
close curObject :#I7);ol
deallocate curObject 0[SJ7k19
GO g.9:R=JPT
10、SQL SERVER中直接循环写入数据 +q NX/F
declare @i int \f6@B:?y
set @i=1 pA|Z%aL
while @i<30 #x^dR-@
begin 9f/RD?(1O
insert into test (userid) values(@i) H,Ik&{@j
set @i=@i+1 %DqPRl.Gu
end n>|7 k3
小记存储过程中经常用到的本周,本月,本年函数 R qnT*
Dateadd(wk,datediff(wk,0,getdate()),-1) `5$B"p&i
Dateadd(wk,datediff(wk,0,getdate()),6) wE*jN~
Dateadd(mm,datediff(mm,0,getdate()),0) ZM$}Xy\9
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) .PHz
Dateadd(yy,datediff(yy,0,getdate()),0) *pMu,?uE
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) .NOh[68'
上面的SQL代码只是一个时间段 bm Hl\?
Dateadd(wk,datediff(wk,0,getdate()),-1) {y0 `p1
Dateadd(wk,datediff(wk,0,getdate()),6) n:i?4'-}
就是表示本周时间段. V/; / &
下面的SQL的条件部分,就是查询时间段在本周范围内的: nGvWlx
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) :j=/>d],%
而在存储过程中 'c")]{
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) (w+dB8)X
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) K@DK4{