1
Q
Connectivity
A
Connectivity: 1:1, 1:M or M:N (three diff ways by which two entities are related).
2
Q
Cardinality
A
cardinality expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity. In the ERD, cardinality is indicated by placing the appropriate numbers beside the entities, using the format (x,y).
3
Q
Connectivity vs cardinality img
A
dd
4
Q
Weak vs strong relationship
A
aa
5
Q
Weak relathiship image
A
a
6
Q
Strong relathionship, weak entity img
A
a
7
Q
Specialization disjoint, overlapping img
A
a
