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。 @jSbMI
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一、基础 lc7a@qnw
1、说明:创建数据库
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CREATE DATABASE database-name @[tV_Z%,b
2、说明:删除数据库 Q4Fq=kTE
drop database dbname RS `9?c:
3、说明:备份sql server -{U>}
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--- 创建 备份数据的 device s%[GQQ-N
USE master rn:zKTyhw
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' V!77YFen %
--- 开始 备份 HJaw\zbL
BACKUP DATABASE pubs TO testBack $>"e\L4Kp
4、说明:创建新表 Qy5Os?9"
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 76A>^Bs\/
根据已有的表创建新表: UlNfI}#X
A:create table tab_new like tab_old (使用旧表创建新表) RF~Ofi
B:create table tab_new as select col1,col2... from tab_old definition only ?koxt44
5、说明:删除新表 @D~+D@i$TW
drop table tabname HXfXb^~
6、说明:增加一个列 Zxc7nLKF~
Alter table tabname add column col type fA_%8CjI
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。
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7、说明:添加主键: Alter table tabname add primary key(col) xD GS`U
说明:删除主键: Alter table tabname drop primary key(col) r}0C8(oq
8、说明:创建索引:create [unique] index idxname on tabname(col....) Np<s[dQ
删除索引:drop index idxname X') Zm+
注:索引是不可更改的,想更改必须删除重新建。 ]TBtLU3
9、说明:创建视图:create view viewname as select statement + sywgb)
删除视图:drop view viewname %8bzs?QI
10、说明:几个简单的基本的sql语句 7AO3-;
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选择:select * from table1 where 范围 O5qW*r'
插入:insert into table1(field1,field2) values(value1,value2) HS\3)Ooj>
删除:delete from table1 where 范围 g+ }s:9
更新:update table1 set field1=value1 where 范围 o)#q9Vk%b
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ~llMrl7
排序:select * from table1 order by field1,field2 [desc] Xqg.kX
总数:select count as totalcount from table1 Ln=>@
求和:select sum(field1) as sumvalue from table1 NSS4vtA
平均:select avg(field1) as avgvalue from table1 =@JS88+
最大:select max(field1) as maxvalue from table1 J1tzHa6
最小:select min(field1) as minvalue from table1 *5y
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11、说明:几个高级查询运算词 Dd0Qp-:2
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A: UNION 运算符 ,@Fgr(?'`>
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。 &[5n0e[
B: EXCEPT 运算符 /&]-I$G@
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 +urS5c*
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C: INTERSECT 运算符 =[P%_v``
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 jby~AJf%
注:使用运算词的几个查询结果行必须是一致的。 W$" Y%^L
12、说明:使用外连接 vuR5}/Ev
A、left outer join: TBZ-17+
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。
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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 XogvtK*
B:right outer join: G{kj}>kS_
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。 dD/t_ {h
C:full outer join: 4}Q O!(
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。 $D QD$
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二、提升 \!^i;1h0c3
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) Ia=_78MgZ
法一:select * into b from a where 1<>1 Z#-k.|}
法二:select top 0 * into b from a n{dP@_>WS
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) lPY@{1W
insert into b(a, b, c) select d,e,f from b; =/6p#d*0
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) S8O)/Sg=
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 tC&fAE:S
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 9nn>O?
4、说明:子查询(表名1:a 表名2:b) `#ul,%
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) %Tfbsyf%f
5、说明:显示文章、提交人和最后回复时间 ))qy;Q,
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b C"y(5U)d
6、说明:外连接查询(表名1:a 表名2:b) dn&s*
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c #NQMy:JHD)
7、说明:在线视图查询(表名1:a ) .j ?W>F
select * from (SELECT a,b,c FROM a) T where t.a > 1; !Z1@}`V&;
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 0j^Kgx
select * from table1 where time between time1 and time2 B`EJb71^Xy
select a,b,c, from table1 where a not between 数值1 and 数值2 l5~os>
9、说明:in 的使用方法 d9k0F
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select * from table1 where a [not] in ('值1','值2','值4','值6') N:^n('U&j
10、说明:两张关联表,删除主表中已经在副表中没有的信息 kXViWOXU^
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) EfqX
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11、说明:四表联查问题: N"Z{5A
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 .....
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12、说明:日程安排提前五分钟提醒 %U/(|wodd
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ^vZSUfS
13、说明:一条sql 语句搞定数据库分页 R7%#U`Q^A
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 ~$ c\JKH-
14、说明:前10条记录 1v y*{D
select top 10 * form table1 where 范围 (|2t#'m
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.) ."g`3tVK
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) B.=FSow
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 .7J#_*NV
(select a from tableA ) except (select a from tableB) except (select a from tableC) RTYvS5G
17、说明:随机取出10条数据 59LG{R2
select top 10 * from tablename order by newid() Usvl}{L[
18、说明:随机选择记录 d z|or9&
select newid() -uS!\
19、说明:删除重复记录 {$oj.V 4
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) <NMEGit
20、说明:列出数据库里所有的表名 b1cy$I
select name from sysobjects where type='U' #`^}PuQ
21、说明:列出表里的所有的 )+#` CIv
select name from syscolumns where id=object_id('TableName') ]U+LJOb
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。 p:&8sO!m
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 "MeVE#O
显示结果: ,CJWO bn3
type vender pcs "69s)~
电脑 A 1 t5Sy V:fP
电脑 A 1 :@Pl pFK
光盘 B 2 Q3'llOx
光盘 A 2 !t"4!3
手机 B 3 Z{*\S0^ST
手机 C 3 & l<.X
23、说明:初始化表table1 YP oSRA L
TRUNCATE TABLE table1 Lj({[H7D!
24、说明:选择从10到15的记录 PI {bmZ
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc RU|Q]Ymx
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三、技巧 "Bkfoi
1、1=1,1=2的使用,在SQL语句组合时用的较多 %UrueMEO
"where 1=1" 是表示选择全部 "where 1=2"全部不选, g _9C*
如: v&\Q8!r_
if @strWhere !='' w7L{_aom
begin b!t0w{^w
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere +Ze}B*0
end hPkp;a #
else =IZT(8
begin ,)cM3nu
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' L(6d&t'|-R
end %uDi#x.
我们可以直接写成 gT.sjd
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere .^`{1%
2、收缩数据库 aqZi:icFa
--重建索引 7sCG^&Y
DBCC REINDEX [(i
DBCC INDEXDEFRAG ~ah~cwmpS
--收缩数据和日志 B`)BZ,#p
DBCC SHRINKDB bIDj[-CDG
DBCC SHRINKFILE _;S-x
3、压缩数据库 >NV@R&
dbcc shrinkdatabase(dbname) J3V=
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4、转移数据库给新用户以已存在用户权限 n`_{9R
exec sp_change_users_login 'update_one','newname','oldname' 6GlJ>r+n
go RMV/&85?y
5、检查备份集 Qp5VP@t
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ;+R&}[9,A)
6、修复数据库 ma]F7dZ5
ALTER DATABASE [dvbbs] SET SINGLE_USER ZDJ`qJ8V
GO ,Fl)^Gl8?
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK gx/,)> E.
GO =ZznFVJ`={
ALTER DATABASE [dvbbs] SET MULTI_USER dES"@?!^
GO Evq IcZ
7、日志清除
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SET NOCOUNT ON y-b%T|p9
DECLARE @LogicalFileName sysname, 1s&zMWC
@MaxMinutes INT, u/0h$l
@NewSize INT WDYeOtc
USE tablename -- 要操作的数据库名 yWc$>ne[L
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 tKuwpT1Qc
@MaxMinutes = 10, -- Limit on time allowed to wrap log. "S]0
@NewSize = 1 -- 你想设定的日志文件的大小(M) 9<?M8_
-- Setup / initialize oSKXt}sh
DECLARE @OriginalSize int 2RX;Ob_
SELECT @OriginalSize = size }-{H Y
FROM sysfiles 8NJqV+jn)t
WHERE name = @LogicalFileName oCv.Ln1;Z
SELECT 'Original Size of ' + db_name() + ' LOG is ' + {w O|)|
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + n38p !oS
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ub0.J#j@
FROM sysfiles Z clQ
WHERE name = @LogicalFileName <$$yw=ef
CREATE TABLE DummyTrans %\#8{g
(DummyColumn char (8000) not null) $)i")=Hy
DECLARE @Counter INT, Et_bH%0
@StartTime DATETIME, Lg+Ac5y}`
@TruncLog VARCHAR(255) +) om^e@.
SELECT @StartTime = GETDATE(), H|<[YYk
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ;8&3 dm]
DBCC SHRINKFILE (@LogicalFileName, @NewSize) NiEUW.0
EXEC (@TruncLog) RLXL&
-- Wrap the log if necessary. ,-LwtePJ0
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired +o{R _
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) M/'sl;
AND (@OriginalSize * 8 /1024) > @NewSize [S%_In
BEGIN -- Outer loop. wmL'F:UP
SELECT @Counter = 0 UhWNl]Z
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) )EuvRLo{S7
BEGIN -- update HWrO"b*tO
INSERT DummyTrans VALUES ('Fill Log') {]!mrAjD
DELETE DummyTrans e]"W!KcD9
SELECT @Counter = @Counter + 1 Fyx|z'4b
END {4}yKjW%z
EXEC (@TruncLog) pj{`';
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END XEp{VC@=
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ]cWUZ{puRB
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 4he GnMD
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Zn+.;o)E<
FROM sysfiles %XDc,AR[
WHERE name = @LogicalFileName HZB>{O
DROP TABLE DummyTrans P )"m0Lu<
SET NOCOUNT OFF 2;`1h[,-^
8、说明:更改某个表 #Y`~(K47
exec sp_changeobjectowner 'tablename','dbo' [ ({nj`
9、存储更改全部表 %N6A+5H
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 2#]#sZmk
@OldOwner as NVARCHAR(128), ~$cV:O7
@NewOwner as NVARCHAR(128) Lx1FpHo
AS KP^V>9q
DECLARE @Name as NVARCHAR(128) `2WFk8) F
DECLARE @Owner as NVARCHAR(128) )[6U^j4
DECLARE @OwnerName as NVARCHAR(128) ZY= {8T@
DECLARE curObject CURSOR FOR <?6|.\&
select 'Name' = name, #U4F0BdA
'Owner' = user_name(uid) Gr'
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from sysobjects bHYy }weZ
where user_name(uid)=@OldOwner NO>w+-dGS
order by name orpri O|qD
OPEN curObject -HbC!wv
FETCH NEXT FROM curObject INTO @Name, @Owner [A~xy'T
WHILE(@@FETCH_STATUS=0) ]NY~2jmX
BEGIN .t-4o<7 3
if @Owner=@OldOwner VBGuC c/
begin 6Q@j
set @OwnerName = @OldOwner + '.' + rtrim(@Name) FaSf7D`C
exec sp_changeobjectowner @OwnerName, @NewOwner $y &E(J
end BwGfTua
-- select @name,@NewOwner,@OldOwner (O?.)jEW(.
FETCH NEXT FROM curObject INTO @Name, @Owner =l;ewlU
END faX#**r
close curObject X1|njJGO1
deallocate curObject Jb@V}Ul$
GO Lc,Pom
10、SQL SERVER中直接循环写入数据 ,j{,h_Op
declare @i int ) 1f~ dR88
set @i=1 Q#X8u-~
while @i<30 K~{$oD7!
begin AaOuL,l
insert into test (userid) values(@i) `/XY>T}-
set @i=@i+1 :yr+vcD?
end Ad8n<zt|
小记存储过程中经常用到的本周,本月,本年函数 wLH>:yKUU
Dateadd(wk,datediff(wk,0,getdate()),-1) bKY7/w<dP
Dateadd(wk,datediff(wk,0,getdate()),6) <n];mfh1
Dateadd(mm,datediff(mm,0,getdate()),0) }Yzco52
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 2DtM20<>
Dateadd(yy,datediff(yy,0,getdate()),0) n8
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) @7]yl&LZ
上面的SQL代码只是一个时间段 !8d{q)JZ
Dateadd(wk,datediff(wk,0,getdate()),-1) ["93~[[^
Dateadd(wk,datediff(wk,0,getdate()),6) kk@fL
就是表示本周时间段. x b~yM%*c
下面的SQL的条件部分,就是查询时间段在本周范围内的: vn!3l1\+J
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 5h-SCB>P
而在存储过程中 Tod&&T'UW
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) &\WSQmtto
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) BC#C9|n