Examine the list of stock quotes in Figure 5-56. Using the structure and example data items in this list, do the following:
A. Create a single-entity data model for this list. Specify the identifier and attributes.
B. Modify your answer to A to include the entities COMPANY and INDEX. Specify the identifier and attributes of the entities and the type and cardinalities of the relationships. Explain which cardinalities can be inferred from Figure 5-56 and which need to be checked out with users.
C. The list in Figure 5-56 is for a quote on a particular day at a particular time of day. Suppose that the list were changed to show closing daily prices for each of these stocks and that it includes a new column: Quote Date. Modify your model in B to reflect this change.
D. Change your model in C to include the tracking of a portfolio. Assume the portfolio has an owner name, a phone number, an e-mail address, and a list of stocks held. The list includes the identity of the stock and the number of shares held. Specify all additional entities, their identifiers and attributes, and the type and cardinality of all relationships.
E. Change your answer to part D to keep track of portfolio stock purchases and sales in a portfolio. Specify entities, their identifiers and attributes, and the type and cardinality of all relationships.
