Author Question: You should not allow nulls in columns that are critical to your business rules. Indicate whether ... (Read 76 times)

panfilo · **on:** Jul 7, 2018

You should not allow nulls in columns that are critical to your business rules.

Indicate whether the statement is true or false

Question 2

Explain many to many relationships and how to deal with them in design.

What will be an ideal response?

stallen · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

TRUE

Answer to Question 2

In a many to many relationship, each record in the primary key table can relate to many records in the foreign key table and each record in the foreign key table can relate to many records in the primary key table. No database management system can implement this kind of relationship. The solution is always to create a linking entity between the two entities with a many to many relationship which resolves the relationship into two one to many relationships.