#1) For chen style erd's, what cardinality symbols do we use (0, 1, N)????? #2) Also, What's the diff between chen style and min, max style? (Please explain using beginner-friendly diagrams)!!!!!
#1) For chen style erd's, what cardinality symbols do we use (0, 1, N)?????
#2) Also, What's the diff between chen style and min, max style? (Please explain using beginner-friendly diagrams)!!!!!
1) For Chen style, what cardinality symbols do we use (0, 1, N)?????
Answer:
The degree of relationship (cardinality) is represented by characters “1”, “N” or “M” usually placed at the ends of the relationships.
one-to-one (1:1)
The employee can manage only one department, and each department can be managed by one employee only:
one-to-many (1:N)
The customer may place many orders, but each order can be placed by one customer only:
many-to-one (N:1)
Many employees may belong to one department, but one particular employee can belong to one department only.
many-to-many (M: N)
One student may belong to more than one student organization, and one organization can admit more than one student
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