Let M and N be two entities in an E-R diagram with simple single value attributes. R₁ and R₂ are two relationship between M and N, where as : R₁ is…
Let M and N be two entities in an E-R diagram with simple single value attributes. R₁ and R₂ are two relationship between M and N, where as : R₁ is one-to-many and R₂ is many-to-many. The minimum number of tables required to represent M, N, R₁ and R₂ in the relational model are _____
Show answerHide answer
Correct answer: (D) 3
Explanation
Two tables are created for entities M and N, and a third table for the many-to-many relationship R₂. R₁ (one-to-many) needs no separate table: the primary key of the 'one' side is placed as a foreign key in the 'many' side. So the minimum is 3 tables.