Cardinality and Modality Essay

CardinalityCardinality indicates the maximum number of multiplication an instance of i entity can be associated with instances in the related entity. Cardinality can have the determine of unmatched or many, no more detail than that. It is either one or more than one. On the relationship line, the cardinality is the closest to the entity box. The cardinality type in the diagram on the slide is in the red circle. Cardinality is indicated at both ends of the relationship line, so there is a left to right cardinality and a right to left cardinality.ModalityModality indicates the minimum number of times an instance in one entity can be associated with an instance in the related entity. Modality can have the values of zero or one, two or three are not allowed. The temper symbol is located next to the cardinality symbol, on the inside, i.e., NOT next to the entity box. A modality of one is denoted by a straight vertical line and a modality of zero is denoted by a circle. Like cardinali ty, modality is indicated at both ends of the relationship.