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。 -Q
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一、基础 E+_&HG}a
1、说明:创建数据库 3&&+YX
CREATE DATABASE database-name bPD)D'Hs
2、说明:删除数据库 9
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drop database dbname ]o.vB}WsY
3、说明:备份sql server \9c$`nn
--- 创建 备份数据的 device ,+/zH'U}
USE master jrJR1npB
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' X'sEE
--- 开始 备份 U)jUq_LX
BACKUP DATABASE pubs TO testBack _]#klL
4、说明:创建新表 =6nD0i9+
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) S4vbN
根据已有的表创建新表: 85U.wpG
A:create table tab_new like tab_old (使用旧表创建新表) _"f :`
B:create table tab_new as select col1,col2... from tab_old definition only 3*S[eqMJc
5、说明:删除新表 @Z(rgF{{
drop table tabname ~&G4)AM
6、说明:增加一个列 $`Nd?\$
Alter table tabname add column col type '8`T|2
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 S0w> hr
7、说明:添加主键: Alter table tabname add primary key(col) MOz}Q1`a
说明:删除主键: Alter table tabname drop primary key(col) Y)HbxFF`/
8、说明:创建索引:create [unique] index idxname on tabname(col....) W*T{,M@Y
删除索引:drop index idxname -/{af
注:索引是不可更改的,想更改必须删除重新建。 <HoAj"xf
9、说明:创建视图:create view viewname as select statement q|#MB7e/
删除视图:drop view viewname mMw;0/n
10、说明:几个简单的基本的sql语句 ma8wmQ9 JR
选择:select * from table1 where 范围 S)\8|ym6!
插入:insert into table1(field1,field2) values(value1,value2) A=3HO\n5
删除:delete from table1 where 范围 y0q#R.TOm
更新:update table1 set field1=value1 where 范围 9w^zY;Y
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! - V) R<
排序:select * from table1 order by field1,field2 [desc] 3P=w =~e
总数:select count as totalcount from table1 z_SagU,\
求和:select sum(field1) as sumvalue from table1 <+E%E4
平均:select avg(field1) as avgvalue from table1 -e`;bX_N)
最大:select max(field1) as maxvalue from table1 -f>'RI95>
最小:select min(field1) as minvalue from table1 I lG:X)V%
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11、说明:几个高级查询运算词 BA+_C]%ZJ
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A: UNION 运算符 iyM^[/-R6
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 r'aY2n^O
B: EXCEPT 运算符 w+UV"\!G)Q
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 h8}8Lp(/'
C: INTERSECT 运算符 g'lT
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 8OAg~mQ15(
注:使用运算词的几个查询结果行必须是一致的。 H~9=&p[Q
12、说明:使用外连接 Z!\@%`0$
A、left outer join: xfHyC'?
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。 !Tfij(91
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 F>Jg~ FD*
B:right outer join: iBbbr,
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。 i ^|@"+
C:full outer join: uEd,rEB>
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。 "E PD2,%S
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二、提升 =7jEz+w#
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) l1-HO
法一:select * into b from a where 1<>1 qi=3L
法二:select top 0 * into b from a :c4kBl%gJ
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) kV)'a
insert into b(a, b, c) select d,e,f from b; #)74X%4(
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) !IAKVQ
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 DX@}!6|T
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. FBYODw
4、说明:子查询(表名1:a 表名2:b) km>o7V&4G
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) Pz473d
5、说明:显示文章、提交人和最后回复时间 {'~sS
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ,IjdO(?TC
6、说明:外连接查询(表名1:a 表名2:b) o/JPYBhdl
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c k&GHu0z
7、说明:在线视图查询(表名1:a ) a!t
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select * from (SELECT a,b,c FROM a) T where t.a > 1; *T4ge|zUc
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 5u,sx664
select * from table1 where time between time1 and time2 R;THA!
select a,b,c, from table1 where a not between 数值1 and 数值2 JSjYC0e
9、说明:in 的使用方法 q|{tQJfYg
select * from table1 where a [not] in ('值1','值2','值4','值6') k>{-[X,/OV
10、说明:两张关联表,删除主表中已经在副表中没有的信息 <o@ )SD~K
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 2V$9ei6
11、说明:四表联查问题: F0;1zw
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... &%e"9v2`
12、说明:日程安排提前五分钟提醒 )BLmoJOf
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 *i?.y*g
13、说明:一条sql 语句搞定数据库分页 6FjVmje
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 q<XcOc5
14、说明:前10条记录 7Po/_%
select top 10 * form table1 where 范围 s/S+ ec3
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) L?f qcW{
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 1URsHV!xcM
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 bOXh|u_3i
(select a from tableA ) except (select a from tableB) except (select a from tableC) ZjD2u8e
17、说明:随机取出10条数据 b\L)m (
select top 10 * from tablename order by newid() %HEmi;
18、说明:随机选择记录 `@$YlFOW
select newid() Ihef$,
19、说明:删除重复记录 LXxl ?D
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) lIl9ypikg
20、说明:列出数据库里所有的表名 ngqUH
select name from sysobjects where type='U' liG~y|
21、说明:列出表里的所有的 LW?2}`+
select name from syscolumns where id=object_id('TableName') /nM*ljfB\
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 4~WlP,,M
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type jr1Se9u D
显示结果: b-b;7a\N
type vender pcs S ljZ~x,!
电脑 A 1 mh8nlB
电脑 A 1 h.LSMU (O
光盘 B 2 B}5XRgq
光盘 A 2 ,CW%JIM
手机 B 3 SA3Y:(
手机 C 3 j&}B<f _6J
23、说明:初始化表table1 ^V,@=QL3U
TRUNCATE TABLE table1 q_58Lw
24、说明:选择从10到15的记录 3mA/Nu_
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Ib(,P3
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三、技巧 ~$ WQ"~z
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, *EE|?vn
如: _^3@PM>
if @strWhere !='' KqY>4tb
begin |Kn^w4mN
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere cFxSDTR
end [r~~=b7*[
else n(# c`t*
begin m-#d8sD2C
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' | &\^n2`>
end 2c*2\93>
我们可以直接写成 C9+Dw#-fV
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere x
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2、收缩数据库 ?/L1tX)
--重建索引 T/3;NXe6E
DBCC REINDEX 'Sk6U]E~
DBCC INDEXDEFRAG #|D:f~"d3
--收缩数据和日志 {&b-}f"m
DBCC SHRINKDB ^)'||Ly
DBCC SHRINKFILE ,DQ
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3、压缩数据库 ],#ZPUn
dbcc shrinkdatabase(dbname) Z~B+*HF
4、转移数据库给新用户以已存在用户权限 QD6Z=>?S
exec sp_change_users_login 'update_one','newname','oldname' l>33z_H^
go XAGiu;<,=
5、检查备份集 $o::PDQ?
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' GYTbeY
6、修复数据库 c{ZqQtfM
ALTER DATABASE [dvbbs] SET SINGLE_USER :4b- sg#
GO 6q!7i%fK?
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 8^NE=)cb7w
GO +0)5H>h
ALTER DATABASE [dvbbs] SET MULTI_USER {S# 5g2
GO OQ
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7、日志清除 ob)D{4B'
SET NOCOUNT ON 7{8)ykBU^
DECLARE @LogicalFileName sysname, Xek E#?.
@MaxMinutes INT, m./*LXU
@NewSize INT %k~C-+
USE tablename -- 要操作的数据库名 (jt*u (C&Y
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 O/'f$ Zj36
@MaxMinutes = 10, -- Limit on time allowed to wrap log. !vi4*
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@NewSize = 1 -- 你想设定的日志文件的大小(M) M |aQ)ivh3
-- Setup / initialize Oym]&SrbS
DECLARE @OriginalSize int >4Fdxa
SELECT @OriginalSize = size !WDn7j'A
FROM sysfiles 7E@$}&E
WHERE name = @LogicalFileName l
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SELECT 'Original Size of ' + db_name() + ' LOG is ' + g!z8oPT
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + J78Qj[v
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' }:tAKO=+
FROM sysfiles 1Z=;Uy\
WHERE name = @LogicalFileName zbdOCfA;
CREATE TABLE DummyTrans UeC 81*XZ
(DummyColumn char (8000) not null) uV#-8a5!
DECLARE @Counter INT, N>h]mX6
@StartTime DATETIME, 1j8 /4:
@TruncLog VARCHAR(255) Cf.WO %?P
SELECT @StartTime = GETDATE(), thR|h+B
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' p PU 2ar
DBCC SHRINKFILE (@LogicalFileName, @NewSize) +lW+H12
EXEC (@TruncLog) iOE9FW|e
-- Wrap the log if necessary. .kz(V5
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ..sJtA8
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) K>`m_M"LA
AND (@OriginalSize * 8 /1024) > @NewSize !;6W!%t.|
BEGIN -- Outer loop. DWHOSXA4
SELECT @Counter = 0 S;G"L$&\
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 75' Ua$
BEGIN -- update *(>F'>F1"
INSERT DummyTrans VALUES ('Fill Log') 8yNRxiW:
DELETE DummyTrans B>c[Zg1
SELECT @Counter = @Counter + 1 ](idf(j
END 99=[>Ck)G
EXEC (@TruncLog) \Or]5ogT'
END 6uv'r;U]
SELECT 'Final Size of ' + db_name() + ' LOG is ' + X:iG[iU*
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + %l0_PhAB
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Z%(Df3~gmm
FROM sysfiles jTGS6{E
WHERE name = @LogicalFileName !:R^}pMhIk
DROP TABLE DummyTrans U]1>?,Nk'3
SET NOCOUNT OFF ci#Zvhtkr
8、说明:更改某个表 i&?
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exec sp_changeobjectowner 'tablename','dbo' q>wa#1X)
9、存储更改全部表 AqTR.}H
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch pRb+'v&_k
@OldOwner as NVARCHAR(128), =+kvL2nx-
@NewOwner as NVARCHAR(128) HQjxJd5P
AS _CYmG"mY
DECLARE @Name as NVARCHAR(128) Y,p2eAss
DECLARE @Owner as NVARCHAR(128) exGhkt~
DECLARE @OwnerName as NVARCHAR(128) +sV# Z,
DECLARE curObject CURSOR FOR 4'7
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select 'Name' = name, CYY
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'Owner' = user_name(uid) 7cJO)cm0'
from sysobjects C"V?yDy2~
where user_name(uid)=@OldOwner X}ey0)g%
order by name ^$g],PAY
OPEN curObject U/v"?pg[
FETCH NEXT FROM curObject INTO @Name, @Owner q|de*~@-P
WHILE(@@FETCH_STATUS=0) y'i:%n}I
BEGIN 4 @ydK
if @Owner=@OldOwner mUe@Dud
begin 2xz%'X%
set @OwnerName = @OldOwner + '.' + rtrim(@Name) xP|%rl4
exec sp_changeobjectowner @OwnerName, @NewOwner FN8=YUYK%
end 3<Pyr-z h
-- select @name,@NewOwner,@OldOwner hA&j?{
FETCH NEXT FROM curObject INTO @Name, @Owner bHlD m~5
END 7J</7\
close curObject _tWfb}6;Zb
deallocate curObject T5X'D(\|
GO 8kn]_6:3i
10、SQL SERVER中直接循环写入数据 l%Fse&4\
declare @i int 0YTtA]|`4
set @i=1 a v|6r#
while @i<30 d%[`=fs]|m
begin E?;T:7.%
insert into test (userid) values(@i) yScov)dp(
set @i=@i+1 _g/TH-;^
end g}s-v?+
小记存储过程中经常用到的本周,本月,本年函数 )b:~kuHi
Dateadd(wk,datediff(wk,0,getdate()),-1) SBYMDKZ
Dateadd(wk,datediff(wk,0,getdate()),6) Bb2r95h}^
Dateadd(mm,datediff(mm,0,getdate()),0) 3R$CxRc:
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) _|5FrN
Dateadd(yy,datediff(yy,0,getdate()),0) JQVw6*u{
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) :6Pc m3
上面的SQL代码只是一个时间段 spoWdRM2
Dateadd(wk,datediff(wk,0,getdate()),-1) TG%hy"k
Dateadd(wk,datediff(wk,0,getdate()),6) ,oi`BOh
就是表示本周时间段. 3I{ta/(
下面的SQL的条件部分,就是查询时间段在本周范围内的: o-e,
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) *Yk8Mj^_h
而在存储过程中 r{N{!"G
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) ws=9u-
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) i2%m}S;D9