关于 class 图中的约束
about constraints in class diagram
取下面的class图：
我想对以下约束进行建模：
一个会员不得在同一天参加多个论文答辩。
我会用限定词来表达给定日期，将有零个或一个论文答辩。这看起来像是关联成员端的一个额外矩形，包含字符串 "defence date : DateTime" 和另一端的 [0..1] 的多重性。请参阅 Qualified Association | Applying UML and Patterns: UML Class Diagrams | InformIT 示例。
如果将 {bag} 附加到多重性，它会告诉 reader 该集合是唯一的。
来自上层建筑 2.1.1：
Various other notations can be placed near the end of the line as follows:
- A multiplicity
- A property string enclosed in curly braces. The following property strings can be applied to an association end:
- {subsets
<property-name>} to show that the end is a subset of the property called <property-name>.
- {redefines
<end-name>} to show that the end redefines the one named <end-name>.
- {union} to show that the end is derived by being the union of its subsets.
- {ordered} to show that the end represents an ordered set.
- {bag} to show that the end represents a collection that permits the same element to appear more than once. • {sequence} or {seq} to
show that the end represents a sequence (an ordered bag).
- If the end is navigable, any property strings that apply to an attribute.
要添加更多的约束条件，例如日期是唯一的，您应该将该约束条件附加到连接器而不是对象。
取下面的class图：
我想对以下约束进行建模： 一个会员不得在同一天参加多个论文答辩。
我会用限定词来表达给定日期，将有零个或一个论文答辩。这看起来像是关联成员端的一个额外矩形，包含字符串 "defence date : DateTime" 和另一端的 [0..1] 的多重性。请参阅 Qualified Association | Applying UML and Patterns: UML Class Diagrams | InformIT 示例。
如果将 {bag} 附加到多重性，它会告诉 reader 该集合是唯一的。
来自上层建筑 2.1.1：
Various other notations can be placed near the end of the line as follows:
- A multiplicity
- A property string enclosed in curly braces. The following property strings can be applied to an association end:
- {subsets
<property-name>} to show that the end is a subset of the property called<property-name>.- {redefines
<end-name>} to show that the end redefines the one named<end-name>.- {union} to show that the end is derived by being the union of its subsets.
- {ordered} to show that the end represents an ordered set.
- {bag} to show that the end represents a collection that permits the same element to appear more than once. • {sequence} or {seq} to show that the end represents a sequence (an ordered bag).
- If the end is navigable, any property strings that apply to an attribute.
要添加更多的约束条件，例如日期是唯一的，您应该将该约束条件附加到连接器而不是对象。