| Q1: | Name three benefits of relationships. |
|
A1:
| The right type of relationship ensures data integrity, optimal performance, and ease of use in designing system objects. |
| Q2: | Explain the concept of a foreign key. |
|
A2:
| A foreign key in one table is the field that relates to the primary key in a second table. For example, whereas CustomerID is the primary key in the Customers table, it may be the foreign key in the Orders table. |
| Q3: | Explain referential integrity. |
|
A3:
| With referential integrity, a database cannot contain any orphan foreign key values. This means that you cannot add child rows for parents that don't exist, you cannot modify the parent key value if that parent has children (unless the Cascade Update Related Fields option is selected), and you cannot delete parents that have children (unless the Cascade Delete Related Fields option is selected). |
| Q4: | Explain the Cascade Update Related Fields option and the Cascade Delete Related Fields option. |
|
A4:
| With the Cascade Update Related Fields option enabled, if the user tries to update the primary key of a parent record that has children, Access updates the foreign key of each of the child rows. With the Cascade Delete Related Fields option enabled, if the user tries to delete a parent record that has children, Access attempts to delete all the associated children rows. |
