Author Question: Deleting tables and relationships is basically a matter of dropping foreign key constraints and then ... (Read 54 times)

evelyn o bentley · **on:** Jul 7, 2018

Deleting tables and relationships is basically a matter of dropping foreign key constraints and then dropping the tables.

Indicate whether the statement is true or false

Question 2

Explain the relationships among primary keys and functional dependencies.

What will be an ideal response?

lkanara2 · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

TRUE

Answer to Question 2

Relations store instances of functional dependencies in their rows. All primary keys represent a functional dependency, since each primary key functionally determines the entire row. Since the primary key determines the entire row, if a primary key were duplicated in a relation, then the entire row would have to be duplicated. Since a relation can contain no duplicate rows, the primary key must be unique.