Draw an Entity-Relationship Diagram (ERD) for the data storage requirements described in the case study below.
Some information in the case study will be conflicting, ambiguous, vague, and/or missing. This should encourage you to think, explore, and search for answers. Seek clarification and/or make reasonable assumptions to complete the requirements: your assumptions and clarifications need to support all details of the ERD that are not already provided by the case study. Document any assumptions you make and clarifications you obtain in an appendix named ‘Assumptions and Clarifications’. There are two options:
1. Seek clarification about the case study by searching the forums. If your question has not already been discussed, please post your question.
2. Make reasonable assumptions about missing or ambiguous information in the case study.However, marks may be lost for unreasonable assumptions. For example, it is unreasonable to assume that people only ever buy one item or one type of item at a time.
• You are encouraged to hand-draw and scan ERDs. Your ERDs should be neat, clear and easy to read. ERDs developed with tool support are acceptable.
• Please follow the modelling standard used in the text book and lecture slides.
• Only use the attributes mentioned in the case study as primary keys. For example, do not introduce surrogate keys not mentioned in the case study.