数据库设计大作业

I’m the owner of a small video rental store. We have over 3,000 movies that we need to keep track of. Each of our movies has a DVD or VHS tape number. For each movie, we need to know its title and category (e.g., comedy, suspense, drama, action, war, or sci-fi).

Yes, we do have multiple copies of many of our movies. We give each movie a specific ID, and then track which DVD or VHS contains the movie. A movie can be either DVD or VHS format.

We always have at least one DVD or VHS tape for each movie we track, and each DVD or VHS tape is always a copy of a single, specific movie.

Our DVDs and VHS tapes are very long. We don’t have any movies that require multiple DVDs or VHS tapes.

We are frequently asked for movies starring specific actors. Mel Gibson and Julia Roberts are always popular. So we’d like to keep track of the star actors

appearing in each movie. Not all of our movies have star actors. Customers like to know each actor’s “real” birth name and date of birth. We track only actors who appear in the movies in our inventory.

We have lots of customers. We rent videos only to people who have joined our 'video club.' For each club member, we’d like to keep their first and last name, current phone number, and current address. And, of course, each club member has a membership number.

Also, we need to keep track of what media each customer currently has checked out. A customer may check out multiple DVDs or tapes at any given time. We really need to keep a history of all our rentals. Each time a customer rents a DVD and/or tape, we would like to keep the rental date/time and the return date/time. All our rentals are due back the next day, so we don’t need to keep a due date.

Keeping this rental history will allow us to analyze the pattern of our rentals. We will be able to determine how many DVD/ tapes each customer rents and how many times a customer has returned a DVD or tape late. We will also know how many times a particular DVD or tape has been used and will then know when to retire each one. We will also be able to analyze our customers’ overall movie preferences.

设计概念模型并转换成逻辑模型

International Movie Rentals Scenario

国际影碟出租场景 翻译：

我是一家小视频租赁商店的主人。我们有超过3000部电影记录在档。我们的每一个电影有一个DVD或VHS磁带号码。每个电影的,我们需要知道它的标题和范畴(例如,喜剧,戏剧、动作、悬疑、战争、或科幻小说)。

是的,我们的许多电影确实有多个副本。我们给每个电影一个特定的身份证（ID）,然后通过这DVD或VHS来找到它包含的电影。电影可以DVD或VHS格式。 我们总是有至少一个DVD或VHS带我们追踪每一部电影（每部电影有多个DVD或VHS）,每一个DVD或VHS磁带总是一份单一、明确的电影（每一个DVD或VHS仅对应一部电影）。

我们的DVD,VHS磁带都很长。我们没有任何电影需要多个dvd或VHS磁带。 我们常常要求具体演员主演的影片。梅尔·吉布森和朱丽娅·罗伯茨总是受欢迎。所以我们要记录出现在每部影片中的影星。我们的电影并不是都有明星演员。客户想知道每一个演员“真实的”出生的姓名和出生日期。但是我们只把出现在电影里的演员记录在我们的清单中。

我们有许多客户。我们的影片只租给那些加入我们俱乐部的人。每一个俱乐部的会员,我们都会保存他们的第一个和最后一个姓名,目前的电话号码,以及目前的地址。当然,每个俱乐部成员有一个会员编号。

同时,我们要记录每一位客户当前借去了什么影片。客户可以在任何特定时间查看多个dvd或磁带。我们真的需要保留一份我们所有租金的历史记录。每一次客户租了一DVD和/或磁带,我们要记录租金日期/时间和返回日期/时间。我们所有的租金是影片归还的第二天截止的,所以我们不需要保留截止日期。

保留租赁的历史记录可以使我们能够分析模式的租金。我们将能够确定每个客户租了的DVD/磁带的租金以及消费者多少次超过了应该归还DVD或磁带的时间。我们也会知道一个特定的DVD或磁带已经被用了多少次，然后就知道每一部影片或磁带该什么时候撤换。我们也能分析客户的整体电影的偏爱喜好。