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Many-to-Many Relationships

This type of relationship takes place when multiple occurrences of an entity are related to multiple occurrences of a second entity.

For example, many employees can be involved in many projects at a given time.

A Many-to-Many relationship is shown on the diagram by a line connecting the two entities with 'crow's foot' symbols at both ends.

Many-to-Many Relationship

Next: The Problem with Many-to-Many Relationships