One to many - relationship cardinality, Database Management System

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One-to-many: An entity in A is related with any number of entities in B. An entity in B is related with at the most one entity in A.

Example: Relationship between faculty and department.

541_One to many - Relationship Cardinality.png

One department can take on any number of faculty members but a faculty member is assigned to only one department.

  • Many-to-one: An entity in A is related with at most one entity in B. An entity in B is related with any number in A.

147_One to many - Relationship Cardinality1.png

Example: Relationship between course and instructor. An instructor can teach several courses but a course can be taught only by one instructor. Please note this is an assumption


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