Question

Parrot Island LLC Parrot Island works with TV and movie producers who need birds that can perform special tricks, such as playing dead, reciting poetry, climbing ladders, and various other tricks. The company has about 50 birds and a list of 20 tricks from which to choose. Each bird can perform one or more tricks. Many tricks can be performed by more than one bird. When a bird learns a new trick. the trainer assigns a skill level. Some customers insist on using birds that score a 10, which is the highest skill level. Birds are characterized by their species, subspecies, size, color, age, name and sex. Each trick is given a name and description. Parrot lsland assigns a bird keeper to a group of birds. Bird keepers take care of their assigned birds. Trainers are responsible for teaching tricks to birds and each trainer is specialized in several tricks. A single veterinarian is responsible for all birds. Below (Figure (a) is the complete ER diagram that shows relationships among birds, skills, keepers, and trainers. BIRD Bird ID SKILL Bird Name Kept by Species Sk Possesses Skill Name Subspecies Description Color Possessed by Size Age Sex TRAINER KEEPER Keeper ID Trains Trainer ID Teaches Keeper Name Tr Name Phone Phone (a)

Answer 1

BIRD Trains TRAINER Bird ID Bird Name Trainer ID Trainer Name Phone Species Subspecies Color Size Age Has a BIRD_TRAINER Bird ID Trainer ID Has a Trains 1. Each bird has a trainer and each trainer trains a bird. Hence the name of the associative entity is "BIRD TRAINER" 2. The attributes are "Bird ID" and "Trainer ID" 3. Attribute types are integers and are foreign keys referring BIRD and TRAINER tables 4. Each bird is trained exactly by one trainer and each trainer may train atleast one bird. 1:1 relationship for between Bird->Trainer and 1:n relationship between Trainer->Bird