数据库应用程序常见T-SQL和PL/SQL-红联Linux系统门户

　　许多软件公司都理解开发不依赖于特定数据库类型(例如，Oracle ， SQL Server ，DB2)的应用程序的重要性，它可以让客户们选择自己习惯的平台。一般来说，软件开发人员都能够识别出他们的负责数据库维护的客户，和必须使用现有平台和个性化的客户。
　　关于Oracle和SQL Server之间的区别，已经有很多篇文章从企业的角度和数据库管理员的角度出发描写了两者之间的一般差别。在这篇文章里面，我将会从应用程序的角度向你描述SQL Server 和Oracle平台之间的区别，并且将会讨论开发不依赖于数据库环境的应用程序的几种可能的方法。

　　与此同时，我不会再论讨对于应用程序来说，两个平台之间显而易见的区别，例如表的分割和索引。

　　定义通用接口和语言

　　有很少的几种通用语言和接口可以让应用程序不依赖于数据库，想来也可以以同样的方式应用在关系型数据库上面:

　　ANSI是美国国家标准局定义的，这是一家志愿者成员的组织(用私人基金运转)，他们在有关设备和程序等广泛领域内开发了国家承认的标准。在数据库领域，ANSI定义了编写SQL 命令的标准，假设命令可以运行在任何的数据库上，而不需要更改命令的语法。

　　ODBC是开放数据库连接(ODBC)接口，微软定义的，它可以让应用程序访问数据库管理系统(DBMS)中的数据，使用SQL 作为访问数据的标准。ODBC允许最大的互联性，这意味着一个单个的应用程序可以访问不同的数据库管理系统。然后，应用程序终端用户可以添加开放数据库连接(ODBC)数据库驱动来将应用程序与他们所选择的数据库管理系统链接上。

　　OLEDB，是ODBC的继承者，是一组允许例如基于VB，C++，Access等任何可以连接到类似SQL Server ，Oracle ，DB2，MySQL等后台的“前台”的软件组件。在许多种情况下，OLEDB组件都比原有的ODBC提供了好得多的性能。

　　JDBC(Java数据库连接)应用程序接口是Java编程语言和广泛范围的数据库，SQL 数据库和其他表列数据源(例如电子表格或者普通文本文件)之间，进行不依赖于数据库的连接的行业标准。JDBD应用程序接口为基于SQL的数据库访问提供了调用级别的应用程序接口。

　　真实世界中的通用接口

　　不幸的是，并不是所有数据库级别的命令都是ANSI，每个数据库平台都有自己的扩展功能。ANSI，或者通用接口，一般来说都代表着几本功能，因此也可能意味着丧失了性能方面的竞争力。对于小型数据库和小型应用程序来说，要维护对数据库的通用访问是简单的，但是当数据库和/或应用程序变得越来越大，越来越复杂，你就不得不向代码中添加功能。

　　示例:

　　在两个平台上以同种方式编写的命令: Insert into Table_1 values (1,'Michelle')
Update Table_2 set Col_1 = 2
Delete from Table_3 where Col_3 like 'Michelle%'

　　在两个平台上不是以同种方式编写的命令: Select getdate()
Select case Fld when 1 then 'a'
When 2 then 'b'
Else 'c'
End
From Table_4
Oracle
Select sysdate from dual
Select DECODE (Fld, 1, 'a', 2, 'b', 'c')
From Table_4

　　下面的两篇文章包括了对Oracle PL/SQL命令和T-SQL命令比较的列表:

　　? 从Oracle移植到SQL Server

　　? 开始学SQL: SQL Server和Oracle之间的区别

72.232.63.* 于 2007-07-01 20:47:43发表:

72.232.63.* 于 2007-07-01 20:46:45发表:

72.232.63.* 于 2007-07-01 20:46:14发表:

72.232.63.* 于 2007-07-01 20:46:00发表:

205.250.167.* 于 2007-07-01 16:34:22发表:

Hi , my sites: :
classical music downloads = music downloads pc = free mp3 music downloads = music downloads pc = Free Music Downloads = Free Music Downloads = Free Music Downloads = music downloads pc = music downloads =
http://musicdownloadsmp3.tripod.com classical music downloads :: http://www.nativeecosystems.org/portal_memberdata/portraits/ge3ei3#freemusicdownloads free music download sites :: http://www.sopadre.com/gallery/louies/music.html legal music downloads :: http://mywebpage.netscape.com/music10free/music-download/ limewire music downloads :: http://hometown.aol.com/mp33music/legal_music_downloads.html Free Music Downloads :: http://musicdownloadsmp3.tripod.com/music_downloads.html free music download :: http://hometown.aol.com/mp33music/legal_music_downloads.html FREE MUSIC DOWNLOADS :: http://mywebpage.netscape.com/bwwfst/Download-Free-Music.htm free music download sites :: http://mywebpage.netscape.com/free5mp3/mp3music.html Free Music Downloads :: http://musicdownloads4free.angelfire.com/free-music.html free legal music downloads :: http://nmstandards.org/portal_memberdata/portraits/vsemoe#musicdownloads free limewire ::
mp3 downloads .. free music downloads .. music download free .. music downloads .. free music .. free download music .. FREE MUSIC DOWNLOADS ..

72.232.63.* 于 2007-06-30 20:25:40发表:

72.232.63.* 于 2007-06-30 20:25:13发表:

72.232.63.* 于 2007-06-30 20:24:14发表:

72.232.63.* 于 2007-06-30 20:23:46发表:

72.232.63.* 于 2007-06-30 20:23:30发表:

58.61.155.* 于 2007-06-29 22:20:50发表:

Greats boys :
free limewire = download free music = free mp3 = FREE MUSIC DOWNLOADS = FREE MUSIC DOWNLOADS = legal music downloads = free music = free mp3 music downloads = Free Music Downloads =
http://musicdownloadsmp3.tripod.com free music :: http://www.nativeecosystems.org/portal_memberdata/portraits/ge3ei3#freemusicdownloads free music for ipod :: http://www.sopadre.com/gallery/louies/music.html mp3 downloads :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music free music downloads :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music free country music downloads :: http://mywebpage.netscape.com/music10free/music-download/ free music ipods :: http://hometown.aol.com/mp33music/legal_music_downloads.html FREE MUSIC DOWNLOADS :: http://musicdownloadsmp3.tripod.com/music_downloads.html free legal music downloads :: http://hometown.aol.com/mp33music/legal_music_downloads.html Free Music Downloads :: http://mywebpage.netscape.com/bwwfst/Download-Free-Music.htm download music free :: http://mywebpage.netscape.com/free5mp3/mp3music.html Free Music Downloads ::
free limewire .. free download music .. FREE MUSIC DOWNLOADS .. free music downloads .. free music download .. limewire music downloads .. music downloads ..

72.232.63.* 于 2007-06-29 22:18:36发表:

72.232.63.* 于 2007-06-29 22:18:05发表:

72.232.63.* 于 2007-06-29 22:17:17发表:

72.232.63.* 于 2007-06-29 22:16:48发表:

72.232.63.* 于 2007-06-29 22:16:33发表:

72.232.63.* 于 2007-06-29 04:06:33发表:

72.232.63.* 于 2007-06-29 04:06:02发表:

72.232.63.* 于 2007-06-29 04:05:16发表:

72.232.63.* 于 2007-06-29 04:04:51发表:

72.232.63.* 于 2007-06-29 04:04:37发表:

88.56.223.* 于 2007-06-28 06:35:08发表:

Hi !!! :
Free Music Downloads = how to download music = free mp3 = FREE MUSIC DOWNLOADS = mp3 downloads = music downloads = music = how to download music = FREE MUSIC DOWNLOADS =
http://musicdownloadsmp3.tripod.com free music video :: http://www.nativeecosystems.org/portal_memberdata/portraits/ge3ei3#freemusicdownloads free music video :: http://www.sopadre.com/gallery/louies/music.html download music free :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music FREE MUSIC DOWNLOADS :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music free music download sites :: http://mywebpage.netscape.com/music10free/music-download/ free music video :: http://hometown.aol.com/mp33music/legal_music_downloads.html free music :: http://musicdownloadsmp3.tripod.com/music_downloads.html free legal music downloads :: http://hometown.aol.com/mp33music/legal_music_downloads.html free music downloads :: http://mywebpage.netscape.com/bwwfst/Download-Free-Music.htm music download :: http://mywebpage.netscape.com/free5mp3/mp3music.html free download music ::
free country music downloads .. free music download .. free mp3 music downloads .. free music downloads .. download music for free .. free ipod music downloads sites .. Free Music Downloads ..

190.74.98.* 于 2007-06-28 06:33:47发表:

212.71.186.* 于 2007-06-28 03:31:11发表:

Hi , my sites: :
free music download sites = free download music = limewire music downloads = Free Music Downloads = mp3 downloads = free music download = free mp3 downloads = download music video = free music downloads =
http://musicdownloadsmp3.tripod.com free music :: http://www.nativeecosystems.org/portal_memberdata/portraits/ge3ei3#freemusicdownloads free music download sites :: http://www.sopadre.com/gallery/louies/music.html free music download :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music FREE MUSIC DOWNLOADS :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music free music ipods :: http://mywebpage.netscape.com/music10free/music-download/ music downloads :: http://hometown.aol.com/mp33music/legal_music_downloads.html free music downloads :: http://musicdownloadsmp3.tripod.com/music_downloads.html FREE MUSIC DOWNLOADS :: http://hometown.aol.com/mp33music/legal_music_downloads.html FREE MUSIC DOWNLOADS :: http://mywebpage.netscape.com/bwwfst/Download-Free-Music.htm free music download :: http://mywebpage.netscape.com/free5mp3/mp3music.html music downloads ::
free mp3 downloads .. free mp3 downloads .. music downloads .. FREE MUSIC DOWNLOADS .. free music download .. free mp3 .. free mp3 downloads ..

61.250.95.* 于 2007-06-28 03:13:54发表:

1Thanks boys :
legal music downloads = download music for free = free country music downloads = Free Music Downloads = free music for ipod = download free music = Free Music Downloads = free music for ipod = free music downloads =
http://musicdownloadsmp3.tripod.com free music ipods :: http://www.nativeecosystems.org/portal_memberdata/portraits/ge3ei3#freemusicdownloads free music download :: http://www.sopadre.com/gallery/louies/music.html free music download :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music free music downloads :: http://www.opensource.wa.gov.au/portal_memberdata/portraits/greg34#music free music downloads :: http://mywebpage.netscape.com/music10free/music-download/ free music ipods :: http://hometown.aol.com/mp33music/legal_music_downloads.html FREE MUSIC DOWNLOADS :: http://musicdownloadsmp3.tripod.com/music_downloads.html free mp3 music downloads :: http://hometown.aol.com/mp33music/legal_music_downloads.html free music downloads :: http://mywebpage.netscape.com/bwwfst/Download-Free-Music.htm free download music :: http://mywebpage.netscape.com/free5mp3/mp3music.html music download ::
download free music .. download music for free .. free music ipods .. free music downloads .. download music free .. free music downloading .. free mp3 downloads ..

72.232.63.* 于 2007-06-26 20:09:09发表:

72.232.63.* 于 2007-06-26 20:08:36发表:

72.232.63.* 于 2007-06-26 20:07:56发表:

72.232.63.* 于 2007-06-26 20:07:33发表:

72.232.63.* 于 2007-06-26 20:07:21发表:

72.232.63.* 于 2007-06-25 19:02:34发表:

72.232.63.* 于 2007-06-25 19:02:09发表:

72.232.63.* 于 2007-06-25 19:01:16发表:

72.232.63.* 于 2007-06-25 19:00:53发表:

72.232.63.* 于 2007-06-25 19:00:38发表:

72.232.63.* 于 2007-06-24 19:11:34发表:

72.232.63.* 于 2007-06-24 19:11:06发表:

72.232.63.* 于 2007-06-24 19:10:11发表:

72.232.63.* 于 2007-06-24 19:09:50发表:

72.232.63.* 于 2007-06-24 19:09:36发表:

数据库应用程序常见T-SQL和PL/SQL

共有 2229 条评论

频道文章

最新教程

随机推荐