Question:

Draw an entity-relationship diagram that describes the following business environment. Must be done by hand, on paper. Not on the computer and include relationship types, ( i.e. Many to many, one to one represented by crows feet etc. 

Central Zoo wants to maintain information about its animals, the enclosures in which they live, and its zookeepers and the services they perform for the animals. In addition, Central Zoo maintains a program by which people can be sponsors of animals. Central Zoo also has to track the food it feeds to its animals.

Each animal has a unique animal number, species, name (Dumbo, Princess, Fred, etc.), gender, country of birth, and date of birth. Enclosures have a unique enclosure number, type (cage, fenced field, etc.), location, size, and date built. An animal can live in only one enclosure. An enclosure can have several animals in it or it can be currently empty.

A zookeeper has a unique employee number, employee name, title, and year hired. Some zookeepers supervise other zookeepers. Every animal has been cared for by at least one and generally many zookeepers; each zookeeper has cared for at least one and generally many animals. Each time a zookeeper performs a specific, significant service for an animal the service type, date, and time are recorded.

Central Zoo has to manage the different kinds of food it feeds its animals. The name of each kind of food (salmon, hay, etc.) is unique. The Zoo has to keep track of the storage requirements (frozen, refrigerated, etc.) for each type of food as well as each foods' freshness period in days. An animal eats only one kind of food; a particular kind of food is fed to several animals.

A sponsor sponsors at least one and possibly several animals. An animal may have several sponsors or none. A sponsor has a unique sponsor number, a name, address, and telephone number. For each animal that a particular sponsor sponsors, the zoo wants to track the annual sponsorship contribution and renewal date.