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。 ?(K=du
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一、基础 !|u?z%
1、说明:创建数据库 |?g-8":H8P
CREATE DATABASE database-name "gm5DE
2、说明:删除数据库 m9:ah<
drop database dbname SvvNk
3、说明:备份sql server w <"mS*Q
--- 创建 备份数据的 device A]i!131{w|
USE master uSQ#Y^V_
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' #\D74$D
--- 开始 备份 [Eu)~J*
BACKUP DATABASE pubs TO testBack ZOa| lB (,
4、说明:创建新表 iJ8Z^=>
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) )mBYW}} T
根据已有的表创建新表: `G`R|B
A:create table tab_new like tab_old (使用旧表创建新表) leH7II9
B:create table tab_new as select col1,col2... from tab_old definition only VR&dy|5BO
5、说明:删除新表 &V<f;PF(I
drop table tabname 3rMJC\h
6、说明:增加一个列 Kn@#5MC
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Alter table tabname add column col type 2=8PA/
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 Q25VG5G
7、说明:添加主键: Alter table tabname add primary key(col) u)o-H!a
说明:删除主键: Alter table tabname drop primary key(col) QQV8Vlv"
8、说明:创建索引:create [unique] index idxname on tabname(col....) =MJB:
删除索引:drop index idxname ~XuV:K3
注:索引是不可更改的,想更改必须删除重新建。 YCxwIzIR
9、说明:创建视图:create view viewname as select statement V|sV U
删除视图:drop view viewname Q{950$)L
10、说明:几个简单的基本的sql语句 gSw<C+
选择:select * from table1 where 范围 zixG}'
插入:insert into table1(field1,field2) values(value1,value2) KT<$E!@
删除:delete from table1 where 范围 h{ix$Xn~
更新:update table1 set field1=value1 where 范围 @d 7V@F0d
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! c$&({Z{1
排序:select * from table1 order by field1,field2 [desc] YOGj__:
总数:select count as totalcount from table1 0\ (:y^X
求和:select sum(field1) as sumvalue from table1 E JuTv%Y8
平均:select avg(field1) as avgvalue from table1 <y^_&9
最大:select max(field1) as maxvalue from table1 @/^mFqr2
最小:select min(field1) as minvalue from table1 zN]%p>,)HB
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11、说明:几个高级查询运算词 QOg >|"KL
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A: UNION 运算符 zN[&
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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。 ,z/aT6M?H
B: EXCEPT 运算符 E/%"%&`8j
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。 w@cW`PlF
C: INTERSECT 运算符 v]F4o1ckk
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。 #*_!Xc9f
注:使用运算词的几个查询结果行必须是一致的。 $>O~7Nfst7
12、说明:使用外连接 g:JSy
A、left outer join: L98T!5)
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 SKnYeT
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c JRFUNy1+e1
B:right outer join: ws!~MSIy
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 +8N6tw/&
C:full outer join: !^su=c
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 =VuSi(d;e{
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二、提升 GK'p$`oJm
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) LPJ7V`!k
法一:select * into b from a where 1<>1 q: FhuOP
法二:select top 0 * into b from a FV
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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) (M$>*O3SR
insert into b(a, b, c) select d,e,f from b; c6 mS
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) -X$EE$:
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 h`1<+1J9
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where..
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4、说明:子查询(表名1:a 表名2:b) UiH7
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) @g5y_G{SP
5、说明:显示文章、提交人和最后回复时间 ]&Y^
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b xLoQ0rt
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6、说明:外连接查询(表名1:a 表名2:b) X7L:cVBg
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c [I4MK%YQ
7、说明:在线视图查询(表名1:a ) G)}[!'<rR
select * from (SELECT a,b,c FROM a) T where t.a > 1; jD9u(qAlH
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 I)FFh%m<}a
select * from table1 where time between time1 and time2 /^nIOAeE
select a,b,c, from table1 where a not between 数值1 and 数值2 OR~ui[w
9、说明:in 的使用方法 #Iz)Mu
select * from table1 where a [not] in ('值1','值2','值4','值6') J}xM+l7uY
10、说明:两张关联表,删除主表中已经在副表中没有的信息 {E Ay~lo
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) H2R3I<j
11、说明:四表联查问题: .UL2(0
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 ..... <nbklo
12、说明:日程安排提前五分钟提醒 8ex;g^e
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 NC-K`)
13、说明:一条sql 语句搞定数据库分页 _`\!+qGq
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 YWH>tt9
14、说明:前10条记录 ;NRh0)%|o
select top 10 * form table1 where 范围 [C6ba{9B
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.) n
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ?}s;,_GH
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 MBA?, |9Q#
(select a from tableA ) except (select a from tableB) except (select a from tableC) 5>f"
17、说明:随机取出10条数据 [%dsq`b#
select top 10 * from tablename order by newid() fS4W*P[B3
18、说明:随机选择记录 sS}:O d
select newid() Io3-\Ff
19、说明:删除重复记录 $Xlr@)%
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) !X-\;3kC0
20、说明:列出数据库里所有的表名 C'$}{%Cc@$
select name from sysobjects where type='U' 'A:Y&w"r
21、说明:列出表里的所有的 :\"0jQ.y|
select name from syscolumns where id=object_id('TableName') G'/GDN^j
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。 +M
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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 4DCh+|r
显示结果: _<.VP
type vender pcs 8~C}0H
电脑 A 1 }bS1M
电脑 A 1 d0I s|Gs
光盘 B 2
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光盘 A 2 ?{f6su@rW
手机 B 3 o1(;"5MM
手机 C 3 Wds>'zzS
23、说明:初始化表table1 c 1F^Gj!8
TRUNCATE TABLE table1 n~yKq"^
24、说明:选择从10到15的记录 a`w=0]1&*
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc >EJ{ *
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三、技巧 H;nzo3x
1、1=1,1=2的使用,在SQL语句组合时用的较多 3O$l;|SX
"where 1=1" 是表示选择全部 "where 1=2"全部不选, `Uz.9_6
如: wz:e\ !
if @strWhere !='' d5gwc5X
begin o-RZwufZ`
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere [y`Gp#
end EZB0qZIp
else -6- sI
begin 8+oc4~!A@n
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' }NC$Ce
end Pt5 wm\
我们可以直接写成 *b) (-#w3
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ^R@)CIQ
2、收缩数据库 (]'wQ4iQ
--重建索引 )?[7}(4jI
DBCC REINDEX f<bB= 9J
DBCC INDEXDEFRAG fW2NYQP$:
--收缩数据和日志 WMtFXkf6"
DBCC SHRINKDB \ 2y/:
DBCC SHRINKFILE lot`6]
3、压缩数据库 S,:!H@~B
dbcc shrinkdatabase(dbname) SnFyK5
4、转移数据库给新用户以已存在用户权限 !u]@Ru34
exec sp_change_users_login 'update_one','newname','oldname' qLLrR,:
go k(H]ILL
5、检查备份集 D*-
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' a.%ps:
6、修复数据库 }~@/r5Zl
ALTER DATABASE [dvbbs] SET SINGLE_USER jnp~ACN,
GO Fc`IRPW<
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK o
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GO yy{YduI
ALTER DATABASE [dvbbs] SET MULTI_USER j%'2^C8
GO BT[|f[1
7、日志清除 !8UIyw
SET NOCOUNT ON moxmQ>xoH
DECLARE @LogicalFileName sysname, ^O7sQ7V"f=
@MaxMinutes INT, *.nSv@F
@NewSize INT 'm*W<
USE tablename -- 要操作的数据库名 > .NLmzUX
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 bxh-#x
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@MaxMinutes = 10, -- Limit on time allowed to wrap log. ZOPK
@NewSize = 1 -- 你想设定的日志文件的大小(M) I=&i &6v8G
-- Setup / initialize H3$py|}lL
DECLARE @OriginalSize int PR|z -T
SELECT @OriginalSize = size :|V650/
FROM sysfiles ?QffSSj[s
WHERE name = @LogicalFileName Y(6evo&IR
SELECT 'Original Size of ' + db_name() + ' LOG is ' + E}9wzPs
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + mF@7;dpr
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ~vDa2D<9%
FROM sysfiles {c)\}s(}F
WHERE name = @LogicalFileName V $I8iVGL
CREATE TABLE DummyTrans 9cB+x`+Lu
(DummyColumn char (8000) not null) P.Bwfa
DECLARE @Counter INT, )I*(yUj
@StartTime DATETIME, eV}" L:bgJ
@TruncLog VARCHAR(255) B\R X
SELECT @StartTime = GETDATE(), $#f_p-N
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 1#3|PA#>
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 6ZE`'pk<
EXEC (@TruncLog) =At" Q6-O
-- Wrap the log if necessary. %R?7u'=~
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 3\}u#/Vb
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) )lLeL#]FLO
AND (@OriginalSize * 8 /1024) > @NewSize 7Q|<6210
BEGIN -- Outer loop. ^dLu#,;
SELECT @Counter = 0 vzs4tkG
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) K!\v?WbF
BEGIN -- update
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INSERT DummyTrans VALUES ('Fill Log') Z#@
DELETE DummyTrans 39O rY
SELECT @Counter = @Counter + 1 oQ-m
END _Vp"G)1Y
EXEC (@TruncLog) 1A'eH:$
END ?`e@ o?
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ?l%4
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + W2rd[W
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' mOj; 0 R
FROM sysfiles
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WHERE name = @LogicalFileName BNJ0D
DROP TABLE DummyTrans
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SET NOCOUNT OFF (rhlK}
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8、说明:更改某个表 o} QP+
exec sp_changeobjectowner 'tablename','dbo' eZa7brC|
9、存储更改全部表 =5*Wu+S4r
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch plPPf+\
@OldOwner as NVARCHAR(128), J|{50?S{^
@NewOwner as NVARCHAR(128)
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AS "XxmiK
DECLARE @Name as NVARCHAR(128) ^cNuEF9
DECLARE @Owner as NVARCHAR(128) swZi
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DECLARE @OwnerName as NVARCHAR(128) >ymn&_zlT
DECLARE curObject CURSOR FOR 34Gu @"
select 'Name' = name, KwHN c\\
'Owner' = user_name(uid) kCD]&
from sysobjects #&)H&H}
where user_name(uid)=@OldOwner ynM:]*~K
order by name ./;uhj
OPEN curObject QWa@?BO2p
FETCH NEXT FROM curObject INTO @Name, @Owner W8bp3JX"
WHILE(@@FETCH_STATUS=0) F8<G9#%s\
BEGIN U&6A)SW,k
if @Owner=@OldOwner (${:5W
begin ,Tar?&C:
set @OwnerName = @OldOwner + '.' + rtrim(@Name) \&+Y;:6
exec sp_changeobjectowner @OwnerName, @NewOwner }*rS g .
end &4evh<z
-- select @name,@NewOwner,@OldOwner 7+f6?
FETCH NEXT FROM curObject INTO @Name, @Owner X<IW5*
END oS$7k3s
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close curObject :(ql=+vDb4
deallocate curObject D$4GNeB+#
GO bL* b>R[x
10、SQL SERVER中直接循环写入数据 Gr\jjf`
declare @i int [;IE Z/ZX
set @i=1 L&s~j/pR
while @i<30 n\D/WLv M
begin `XE>Td>Bs
insert into test (userid) values(@i) Dks n
set @i=@i+1 Drtg7v{@\
end OKm,iIp]
小记存储过程中经常用到的本周,本月,本年函数 G{6@]72
Dateadd(wk,datediff(wk,0,getdate()),-1) )jl@hnA
Dateadd(wk,datediff(wk,0,getdate()),6) : 8>zo
Dateadd(mm,datediff(mm,0,getdate()),0) I2HV{1(i
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) |~%RSS~b*
Dateadd(yy,datediff(yy,0,getdate()),0) Sak^J.~G[
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) |MKR&%Na
上面的SQL代码只是一个时间段 kJ"rRsK
Dateadd(wk,datediff(wk,0,getdate()),-1) kwUUvF7w
Dateadd(wk,datediff(wk,0,getdate()),6) 1@{ov!YB]
就是表示本周时间段. d+)L K~
下面的SQL的条件部分,就是查询时间段在本周范围内的: ~l:Cj*6x8
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ssQ1u.x9
而在存储过程中 ^A&{g.0
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) (*r2bm2FPO
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ]T/%Bau