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。 E2r5Pg
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一、基础 V.:,Q
1、说明:创建数据库 )!27=R/
CREATE DATABASE database-name 2*V%S/cck
2、说明:删除数据库 uSR%6=$
drop database dbname _MC',p&
3、说明:备份sql server Eh8GqFEM
--- 创建 备份数据的 device DQY1oM)D!
USE master .zZfP+Q]8
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' gGvL6Fu
--- 开始 备份 qY8; k
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BACKUP DATABASE pubs TO testBack >KuNHuHu
4、说明:创建新表 n~6$CQ5dF(
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) u!D?^:u=)
根据已有的表创建新表: a?+C]u?_D
A:create table tab_new like tab_old (使用旧表创建新表) c;]\$#2
B:create table tab_new as select col1,col2... from tab_old definition only \;Q(o$5<
5、说明:删除新表 Jn{)CZ
drop table tabname O~qRHYv
6、说明:增加一个列 C&Q[[k"kb
Alter table tabname add column col type lVT*Ev{&.
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 4ct-K)Ris
7、说明:添加主键: Alter table tabname add primary key(col) !QwB8yK@
说明:删除主键: Alter table tabname drop primary key(col) <lFHmi$qt{
8、说明:创建索引:create [unique] index idxname on tabname(col....) esTL3 l{[
删除索引:drop index idxname t#P7'9Se8
注:索引是不可更改的,想更改必须删除重新建。 |.Vgk8oTl
9、说明:创建视图:create view viewname as select statement v];YC6shx
删除视图:drop view viewname 8i]
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10、说明:几个简单的基本的sql语句 (Z>?\iNJ
选择:select * from table1 where 范围 mh"PA p
插入:insert into table1(field1,field2) values(value1,value2) o=Z:0Ukl]
删除:delete from table1 where 范围 *Hn=)q
更新:update table1 set field1=value1 where 范围 zqj|$YNC
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Fxa{
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排序:select * from table1 order by field1,field2 [desc] ,|RKM
总数:select count as totalcount from table1 JvXuN~fI{[
求和:select sum(field1) as sumvalue from table1 poafGoH-Y
平均:select avg(field1) as avgvalue from table1 E'{:HX
最大:select max(field1) as maxvalue from table1 @lDnD%vZ`
最小:select min(field1) as minvalue from table1 n>u_>2Ikkj
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11、说明:几个高级查询运算词 bJMsB|r
t }4
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A: UNION 运算符 !q$VnqFk
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。 &w^9#L
B: EXCEPT 运算符 vGsAM*vw6
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。 vh.8m$,
C: INTERSECT 运算符 t"Du
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 <UO[*_,\
注:使用运算词的几个查询结果行必须是一致的。 ^E/6vG
12、说明:使用外连接 cRKLyb
A、left outer join: 8OOAPp$%|
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 vWmt<E|e
B:right outer join: VM5'd
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。 ugN%8N
C:full outer join: 02EX_tt),
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。 pSQX
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二、提升 /
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1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) *Jcd_D\-(1
法一:select * into b from a where 1<>1 2|?U%YrHWs
法二:select top 0 * into b from a c86?-u')
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) }f;TG:6
insert into b(a, b, c) select d,e,f from b; 1:<n(?5JI
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) p}==aNZK
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 lmcgOTT):
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. mN{H^
4、说明:子查询(表名1:a 表名2:b) zfDfy!\2_
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) el$@^Wy&$
5、说明:显示文章、提交人和最后回复时间 yq x!{8=V
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b en|~`]HF
6、说明:外连接查询(表名1:a 表名2:b) ~1TT ?H
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c V(K;Gc
7、说明:在线视图查询(表名1:a ) t|V5[n!
select * from (SELECT a,b,c FROM a) T where t.a > 1; j8Q_s/n
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 ^vh!1"T
select * from table1 where time between time1 and time2 XC<'m{^(m
select a,b,c, from table1 where a not between 数值1 and 数值2 \'g7oV;>cI
9、说明:in 的使用方法 <
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select * from table1 where a [not] in ('值1','值2','值4','值6') [}Xw/@Uc;
10、说明:两张关联表,删除主表中已经在副表中没有的信息 Wx#l}nD
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
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11、说明:四表联查问题: j@nK6`d+1
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 ..... JO]?u(m01
12、说明:日程安排提前五分钟提醒 LR.]&(kyd
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 !_+FuF"@
13、说明:一条sql 语句搞定数据库分页 _)pOkS
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 *eXs7 "H
14、说明:前10条记录 |#t^D.j
select top 10 * form table1 where 范围 !ck luj
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.) 4J'0k<5S
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) /AX)n:,
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 `yl|NL
(select a from tableA ) except (select a from tableB) except (select a from tableC) {TJ"O
17、说明:随机取出10条数据 d\Up6F
select top 10 * from tablename order by newid() jK\kASwG
18、说明:随机选择记录 SefF Ci%4
select newid() yo_zc<
19、说明:删除重复记录 J s33S)
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) n=DmdQ}
20、说明:列出数据库里所有的表名 #(}{*dR
select name from sysobjects where type='U' p:tp|/
21、说明:列出表里的所有的 'Kmf6iK>[
select name from syscolumns where id=object_id('TableName') i\
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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。 cfBlHeYE
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 %t* 9sh
显示结果: Q>X1 :Zn3
type vender pcs pdN8hJ
电脑 A 1 u*\QVOF
电脑 A 1 dw}ge,bBic
光盘 B 2 DI-&P3iGx
光盘 A 2 oEZhKVyc.y
手机 B 3 =j w?*
手机 C 3 zvnd@y{[
23、说明:初始化表table1 +`S_Gy
TRUNCATE TABLE table1 evE:FiDm(j
24、说明:选择从10到15的记录 DV?c%z`YO
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ae3 Gn}tf
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三、技巧 .j)DE}[q>
1、1=1,1=2的使用,在SQL语句组合时用的较多
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, |w~*p
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如: (:H4
if @strWhere !='' oKkDG|IE
begin dJQwb
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere vfDX~_N
end Iza#v0
else yHf^6|$8
begin {J)gS
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 6R3/"&P(/#
end Y*jkUQ
我们可以直接写成 NP\/9
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere aY,'^S
2、收缩数据库 Y^#>3T
--重建索引 >;M STHeW
DBCC REINDEX 6ypHH
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DBCC INDEXDEFRAG g("[wqgG
--收缩数据和日志 NeEV=+<-G
DBCC SHRINKDB [p0_I7
DBCC SHRINKFILE W`#E[g?]
3、压缩数据库 ^=-W8aVi>
dbcc shrinkdatabase(dbname) #="Lr4T
4、转移数据库给新用户以已存在用户权限 >Wd=+$!I
exec sp_change_users_login 'update_one','newname','oldname' j}}as
go oO
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5、检查备份集 P|f h4b4
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' N-<,wUxf
6、修复数据库 ?6\A$?
ALTER DATABASE [dvbbs] SET SINGLE_USER 9,>c;7s X
GO (A_H[xP
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK .`D$.|!8g
GO d_V7w4lK
ALTER DATABASE [dvbbs] SET MULTI_USER v~dUH0P<>e
GO `ST;";7!
7、日志清除 N4yQ,tG>aa
SET NOCOUNT ON LmR OG-9
DECLARE @LogicalFileName sysname, 1TN+pmc}@
@MaxMinutes INT, ?ZKIs9E[m
@NewSize INT ]K5j(1EN
USE tablename -- 要操作的数据库名 <&1hJ)O
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 V22Br#+
@MaxMinutes = 10, -- Limit on time allowed to wrap log. f0{tBD!%
@NewSize = 1 -- 你想设定的日志文件的大小(M) up?S (.*B
-- Setup / initialize d$MewDWUN
DECLARE @OriginalSize int \rbvlO?}
SELECT @OriginalSize = size 8Sf}z@~]
FROM sysfiles 9M[
WHERE name = @LogicalFileName DQN"85AIZ
SELECT 'Original Size of ' + db_name() + ' LOG is ' + bHs},i6
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + NU7k2`bqAk
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' TDR#'i
FROM sysfiles wD pL9 q
WHERE name = @LogicalFileName lz#@_F|.*
CREATE TABLE DummyTrans NQbgk+&wD
(DummyColumn char (8000) not null)
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DECLARE @Counter INT, ]MMXpj,9h
@StartTime DATETIME, RL"hAUs_1
@TruncLog VARCHAR(255) )4w3$Q
SELECT @StartTime = GETDATE(), 90Z4saSUw
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' SzjylUYV
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ]4_)WUS.c
EXEC (@TruncLog) ]A_A4=[w
-- Wrap the log if necessary. mL s>RR#b
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 3SF J8
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 59_VC('
AND (@OriginalSize * 8 /1024) > @NewSize b~rlh=(o#_
BEGIN -- Outer loop. }Mc&yjhMrg
SELECT @Counter = 0 _#E@&z".L
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) \T`iq[+6
BEGIN -- update d^aLue>g;+
INSERT DummyTrans VALUES ('Fill Log') 3)dtl!VMW[
DELETE DummyTrans =fK F#^E@
SELECT @Counter = @Counter + 1 u|ru$cIo
END Eds{-x|10
EXEC (@TruncLog) "SwM%j
END d6e]aO=g
SELECT 'Final Size of ' + db_name() + ' LOG is ' + LaIH3!M3
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 2s`~<EF N
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' n#5 pd;!n
FROM sysfiles "4QD\k5
WHERE name = @LogicalFileName &,=t2_n
DROP TABLE DummyTrans G"prq&
SET NOCOUNT OFF yuZhak
8、说明:更改某个表 AcY!
exec sp_changeobjectowner 'tablename','dbo' d
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9、存储更改全部表 yuB\Z/
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 8&y3oxA,
@OldOwner as NVARCHAR(128), ^ G>/;mZ
@NewOwner as NVARCHAR(128) =/^{Pn
AS EK^["_*A
DECLARE @Name as NVARCHAR(128) u6p
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DECLARE @Owner as NVARCHAR(128) V34]5
DECLARE @OwnerName as NVARCHAR(128) J*f..:m
DECLARE curObject CURSOR FOR v<S?"#
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select 'Name' = name, +JBYGYN&K
'Owner' = user_name(uid) n0@ \x=9
from sysobjects + gP 4MP
where user_name(uid)=@OldOwner F='rGQK!1
order by name }mQh^
OPEN curObject *| YR8f
FETCH NEXT FROM curObject INTO @Name, @Owner C@FX[:l@-
WHILE(@@FETCH_STATUS=0) rWzO>v
BEGIN [YQ` `
if @Owner=@OldOwner sJ cwN.s
begin [-x]%
set @OwnerName = @OldOwner + '.' + rtrim(@Name) P*8DM3':
exec sp_changeobjectowner @OwnerName, @NewOwner %-, -:e
end 9y&&6r<I
-- select @name,@NewOwner,@OldOwner 7{DSLKtN
FETCH NEXT FROM curObject INTO @Name, @Owner E\=23[0
END F5EsaF'e4
close curObject 3ES3,uR
deallocate curObject 8#~x6\!b
GO pr"~W8
10、SQL SERVER中直接循环写入数据 h*X
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declare @i int gK"E4{y_@
set @i=1 JNgl
while @i<30 wWUt44:0O
begin &H@OLyC
insert into test (userid) values(@i) km#Rh^
set @i=@i+1
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end _,9/g^<
小记存储过程中经常用到的本周,本月,本年函数 6`hHx=L
Dateadd(wk,datediff(wk,0,getdate()),-1) o;Ma)/P
Dateadd(wk,datediff(wk,0,getdate()),6) 9"mcN3x:\e
Dateadd(mm,datediff(mm,0,getdate()),0) LIDYKKDJ^
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) hNJubTSE+)
Dateadd(yy,datediff(yy,0,getdate()),0) p4'Qki8Hd
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) FrBJv<
上面的SQL代码只是一个时间段 /\1MG>#K
Dateadd(wk,datediff(wk,0,getdate()),-1) V9i[dF
Dateadd(wk,datediff(wk,0,getdate()),6) _^pg!j[Fy}
就是表示本周时间段. h\qM5Qx+Q
下面的SQL的条件部分,就是查询时间段在本周范围内的: SPK%
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Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6)
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而在存储过程中 d|(@#*{T]
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) -&\?Q_6
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) F~_)auH