An attribute that uniquely identifies an entity and consists of a composite attribute is called a(n): Show An entity that associates the instances of one or more entity types and contains attributes specific to the relationships is called a(n): The number of entity types that participate in a relationship is called the: A relationship between the instances of a single entity type is called a(n) ________ relationship. A student can attend five classes, each with a different professor. Each professor has 30 students. The relationship of students to professors is a ________ relationship. A ________ specifies the number of instances of one entity that can be associated with each instance of another entity. A simultaneous relationship among the instances of three entity types is called a(n) ________ relationship. A relationship where the minimum and maximum cardinality are both one is a(n) ________ relationship. A value that indicates the date or time of a data value is called a(n): A mutually exclusive relationship is one in which: an entity instance can participate in only one of several alternative relationships. Is an attribute or combination of attributes that uniquely identifies each instance of an entity type?The primary key is an attribute or a set of attributes that uniquely identify a specific instance of an entity. Every entity in the data model must have a primary key whose values uniquely identify instances of the entity.
Which of the following is a generic entity type that has a relationship with one or more subtypes?A supertype is a generic entity type that has a relationship with one or more subtypes. A subtype is a sub-grouping of the entities in an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other subgroups.
What is an entity What are entity instances?Whereas an entity type represents an abstract category, an entity instance is a manifestation of an entity within that category. For example, Cell could be the entity type, but Cell_1 , Cell_2 , and Cell_3 would represent the actual items within the network.
What are the types of entity?An entity can be of two types :. Tangible Entity : Entities that exist in the real world physically. Example: Person, car, etc.. Intangible Entity : Entities that exist only logically and have no physical existence. Example: Bank Account, etc.. |
What is the entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances?
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