一对多关系

• Even though a controller typically controls several agents , an agent is controlled by a single controller
  控制器和代理之间存在着一对多关系。每个代理只由一个控制器控制。
• Make a one - to - many relationship if only one of the related columns is a primary key or has a unique constraint
  如果在相关列中只有一列是主键或具有唯一约束，则创建一对多关系。
• Because each customer can have more than one order , there is a one - to - many relationship between customers and orders
  因为每个顾客可以有一个以上的订单，所以在顾客和订单之间存在一对多关系。
• Explains how to programmatically return related records in a typed dataset with tables in a one - to - many relationship
  介绍如何通过编程方法返回具有一对多关系的表的类型化数据集中的相关记录。
• Tables have a one - to - many relationship : each publisher produces many titles , but each title comes from only one publisher
  表具有一对多关系：每个出版商出品很多书，但每本书只出自一个出版商。
• If a relationship has a key at one endpoint and a figure - eight at the other , it is a one - to - many relationship
  如果某个关系在一个终结点处有键，在另一个终结点处有无穷符号，则该关系是一对多关系。
• You create a schema with one - to - many relationships when xml files contain related elements that are hierarchically at the same level
  当xml文件包含处于层次结构中同一级别的相关元素时，可创建带有一对多关系的架构。
• There are three main steps involved in creating an xml schema that will be used to validate data that is structured in a one - to - many relationship
  创建xml架构（将用于验证结构为一对多关系的数据）涉及的步骤主要有三个。
• Customers . this differs from a one - to - many relationship where all customer information , as well as order information , would hierarchically exist at the same level and be related through the use of keys and keyrefs
  这与一对多关系不同，在一对多关系中，所有客户信息以及订单信息均在层次结构中的同一级别中，通过使用键和keyref联系起来。
• In this way , mobile monitoring system has self - adaptability and fault tolerant ability . ( 5 ) basic functions of this system are implemented by software programming . the model studied in this paper not only satisfies the requirement of mobile monitoring of digital meters , but also applies to other mobile application system , therefore , this model has great scientific research value and broad prospect
  本文研究设计的可交互的、智能的、易扩展的、移动终端和监视端之间一对多关系的数字仪表的移动监视模型不仅满足数字仪表的移动监视需求,而且还可以将此模型应用到其他移动应用系统中,因而具有较高的研究价值和一定的实用价值。