Understanding entity relationship diagrams
By performing an entity analysis, you analyze a process or a part of a process. You focus on the data used in that process. What data do you need? Take, for instance, a planner. What do they need to know to be able to do the planning? In addition, you look at the results of the process. You store the results of whatever was planned.
As another example, a store needs to keep track of which products will be sold for what price. The sales department needs to know which customers buy what kind of products and for what amounts and what the costs are to be able to sell those products. All this information needs to be stored somewhere in the database. Looking again at an online shop, you need to store data about customers, products, and orders. These are the entities involved in this process. Entities are specific objects in the world you want to store data about. Entities will be defined in the next section. Entities become tables in our databases...