老马说：A single instance that handles the business logic for all rows in a database table or view.我说：一个实例操作所有一个数据库表或视图的业务逻辑。One of the key messages of object orientation is bundling the data with the behavior that uses it面向对象设计的一个关键点是把数据和操作他们的行为包装在一起。The traditional object-oriented approach is based on objects with identity, along the lines of Domain Model 。传统的面向对象设计方法是建立在对象的一致性基础之上的，沿着业务对象链。哈哈Thus, if we have an Employee class, any instance of it corresponds to a particular employee.因此，如果我们有一个（Employee类），所有它的实例符合一个特殊的（Employee）。This scheme works well because once we have a reference to an employee, we can execute operations, follow relationships, and gather data on him.这个设计能很好的工作，因为一但我们有一个对象的接口，我们就可以执行它的方法，关联关系，和在它身上收集数据。One of the problems with Domain Model (116) is the interface with relational databases. 业务对象的一个问题在于和关系数据库的交互。 In many ways this approach treats the relational database like a crazy aunt who's shut up in an attic and whom nobody wants to talk about. 许多时候这种办法不能处理关系型数据库。As a result you often need considerable programmatic gymnastics to pull data in and out of the database, transforming between two different representations of the data.结果是你通常要考虑怎么把数据从数据库中取出插入，使其在不同的表现方式上转换。A Table Module organizes domain logic with one class per table in the data-base, and a single instance of a class contains the various procedures that will act on the data. Table Module用一个在数据库中的表来组织业务逻辑，它的一个实例包含许多不同的操作数据库的方法。The primary distinction with Domain Model (116) is that, if you have many orders, a Domain Model (116) will have one order object per order while a Table Module will have one object to handle all orders.和业务对象最大的不同是，如果你有许多的Orders，一个业务对象用一个Order对象来表达一个Order，而Table Module则用一个对象来表示所有的Orders。
转载于:https://www.cnblogs.com/nanshouyong326/archive/2006/12/02/579693.html
相关资源：数据结构—成绩单生成器