Relational Schema

Sample Data

Playtime with Telly

The pet toy company, Pets of the Future, wants to know which cat toys are the most popular and of best sale value. Therefore, they created a database of the cat Telemachus' (te-lem-uh-cuss) toys, with his owner, Jenny's, permission. Pets of the Future has modified Telly's toys (and potential toys) with tracking devices and playtime counters. Each time Telemachus plays with a toy, the information is automatically recorded in the database entitled "Playtime with Telly."

The project has four helpers: Telemachus' "Mummy" Jenny, his Aunties Ruth and Corinne, and his grandmother Susan, the source of many of his toys. The helpers make sure that the database tracks the toys correctly and record any accidental "playing", i.e. "Mummy" accidentally sucked the toy up with the vacuum cleaner.

The main entity is titled "Cat Toys." Mummy, the Aunties, or Telly when he's feeling terribly inspired, record general information about each toy when it first enters the apartment. This information includes id number, color, rating, and lendability. The id number is unique and corresponds with the tracking devices. The color column helps the humans in the apartment identify each toy and the company to determine whether one color is more popular than the others. Rating is determined by how often Telemachus plays with the toy; it has an initial rating of 1, i.e. undesirable toy. The final column, lendability, is to determine the availability of a particular toy. Did Telly bring the toy with him when he visited his grandmother? Are his sisters, Thisbe and Isis, currently playing with the toys at Grandmother's house? Or did the cat next door, Jupiter, "borrow" the toy? All of these factors would be important in determining whether or not a particular toy is in use.

Another entity is "Type." This has information about the type of toys, i.e. mouse, ball, feather, stuffed-animal, bookmark, milk-jug ring, tail. It also has a general description of each type of toy.

A third entity is "Locations." This entity is directly connected to the tracking system and is updated automatically. It records whether or not the location is used for hiding toys and in which room the toy is located. The entity also includes the exact GPS coordinates of the toy.

The fourth entity is "Use." Connected with the tracking micro-chip is a playtime counter. This counter records start time, end time, and generates total time of use. The foreign key points back to Cat Toys. This information then generates a new rating for the cat toy in the "Cat Toy" entity.

The "Givers" entity stores information on the toys' initial source. Pets of the World uses this information to determine the market for the toys. It gives each "giver" an id number, records the name (first and last), the relationship to Telemachus, and the rating of the toy. It is connected to the Address entity, which records the giver's address. The data generated from these tables helps Pets of the World understand their market.

The "Borrowers" entity records vital information on "lent" toys. It records the name of the borrower. For example, Thisbe. It also has a yes/no field for friend. Is Thisbe Telemachus' friend? No. It also records the relationship between the two cats. In this example, Thisbe's relationship to Telemachus is "older sister." This entity is also connected to the Address table. Thisbe's id would show that she lives with Telly's Grandparents.

This database could answer the following queries. 1) Where is the yellow mouse with id number 001? 2) Who has Mummy's bookmark? 3) Who gave Telemachus the scratching post with the floating feathers (id number 223)? 4) How does Telly rate the (or all) green rubber ball(s)? 5) How many mice does Telly have? 6) How much time has been spent playing with the fishing pole? 7) Is Isis a friend? Where does she live? Does she have any of Telly's toys? 8) How many toys does Telly have?

Creators: Jenny Freed, Corinne Michels, Ruth Whittington

ER Diagram

Relational Schema

Sample Data