Entity Relationship Data Model And Normalization Computer Science Essay Example

Design an Entity-Relationship Data Model that outlines the data content and structure maintained by Petcare. Include the cardinality ratio and participation constraint for each relationship type. To create the Petcare database system, it is necessary to construct an Entity Relationship Diagram that depicts all entities and their relationships.

The ERD depicts the static connections between data that are stored and managed by the database. It illustrates the static relationships among data items. The next step involves determining the relationship of each entity, which includes Participation Constraint and Cardinality Ratio. In terms of Participation Constraint:

1. There are two types of participation constraint: 'Total' and 'Partial' participation.
2. A 'Total' participation constraint (mandatory participation) specifies that every member in the entity must participate as a m
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   ember of another linked entity in the generalization.

3. A 'Partial' participation constraint (optional participation) specifies that a member of the entity does not belong to any member of another linked entity in the generalization.

Cardinality Ratio refers to a one-to-one relation between two entities that are linked solely by their primary key(s).

The text discusses various relationships between entities in a database. The first type of relationship is called many-to-many, where two entities are connected without a primary key and may have redundancy errors. It is advisable to split this type into two relations: one-to-many and many-to-one. The second type, known as one-to-many or many-to-one, involves a relationship between two entities where the primary key(s) link to the foreign key(s). Moreover, the text presents an example of the Pet relationship in which each pet ha