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Archive for August, 2006|Monthly archive page

标识关系与非标识关系的区别

In programming on August 29, 2006 at 11:54 AM

最近在用Rose画数据库的数据模型设计图,画出来的不是ER图,但是和ER图比较相近。不过里面有两个概念一直没搞懂,identifying/non-identifying relationship,仔细查了一下,有不少介绍这个知识的文章。

从结果来看的话,identifying关系中的子表必须将父表的外键作为主键,而non-identifying则不必。

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Goodbye ink

In learning, other on August 20, 2006 at 9:48 AM

前段时间帮同学写了一篇英语作文,主题是“信息时代传统书籍是否还有存在的必要”,今天整理的时候翻了出来,post到这里,立此存照。可惜字数要求在200字左右,很多东西都没写清楚,感觉没写够:-(

Good bye ink

With the advent of the Internet era, computers play a more and more important role in our life. Increasingly more information is delivered through the Internet rather than the traditional ink-based media, such as newspaper and books. In my humble opinion, the daily newspaper and books will be vanishing away, sooner than you think.
In such an information-exploded world, newspaper could not keep pace with the change of things. The zippergate scandal of Bill Clinton was unveiled by an unknown blogger, and the 9/11 attacks was mainly reported through thousands of sites in the Web. People are accustomed to acquire the latest news from their favourite websites rather than the newspaper they subscribed. Power has moved from the old elite to bloggers.
In the same era, more books are digitized. What are the advantages of digital books? Let me count the ways. I don’t have to decide what to take on holiday to read; I just take my whole library. Colour is free: it costs no more to produce a colour book than a black and white one. Publishing costs are really low, and amateurs can publish books just as easily as publishers can. Small language groups can afford to keep their literature available. There’s no need to go on. Although real books smell nice, it’s inevitable that they will be eliminated in the near future.
To sum up, our generation will finally witness the demise of these traditional media. It is with a mixture of great sorrow and joy, in the same time, it is signiture of social progress and is unavoidable to happen.

这是引用了信息指纹及其应用一贴的某篇文章

In idea, other on August 10, 2006 at 9:21 PM

一直看GoogleChinaBlog,很想在上面留个言,不过那里好像不提供留言功能的说,唯一的留下自己痕迹的方法好像就剩下Backlink了.今天就借个机会backlink一下,本来还想顺便给自己的blog也加上backlink的功能的,不过好像本人RP实在太差,导致PR值也不高,”link:blog.niyue.com“在Google上面搜索了一下居然一个站点也没有链接到这里,加到这里反而变成自取其辱了,实在不能满足本人blogger ego的需要,于是就放弃了.
本来还想借这篇文章顺便提高一下PR值的(backlink了GoogleChinaBlog之后也会被link到GoogleChinaBlog上,不知道Google自己的网站连出去的站点会不会特地提高一下PR^_^),不过发现这种SEO的策略是行不通的,只能希望Google的爬虫还爬的到这里能够找到这个backlink,这样还能够借GoogleChinaBlog带点人气呵呵,如果你是通过GoogleChinaBlog上的信息指纹及其应用这篇文章surfing到这里来的,麻烦请留个名让我知道一下:-)