Question 6 A database that conforms to an E/R diagram can be represented by a collection of tables…

A database that conforms to an E/R diagram can be represented by a collection of tables in the relational system. Let us discuss the mapping of E/R diagrams to tables in relation to the following:

• Regular entities
• Attributes
• Relationships
• Weak entities
• Sub-types and Super-types

1. Q.6.1 Explain the concept of a sub-type, super-type relationship.
2. Q.6.2 Explain the concept of a weak entity.
3. Q.6.3 Draw an Entity Relationship Diagram that illustrates subtypes and super-types.

Question 7

Creating a database plan gives a clear idea about the kind of database that is needed. Explain five (5) advantages of good database planning.

Question 8

Please draw and label a full detailed diagram of the below ERD:

Mountain Parcel Services (MPS) deliver products on behalf of their customers all over the world. MPS has hired you to design an ER diagram. Many products are delivered to many customers on a daily basis. MPS employs full time and external drivers to deliver products. The drivers collect the products from a single warehouse that stores the products until a driver collects it for delivery.

Draw an ER diagram to represent the above situation. Include in your answer the following:

• Entities
• Three (3) attributes per entity (one of which must be a primary key)
• Relationships