LU04.S07 - ERD: Reingineering of an existing database

Task

Go to the W3Schools-Website, to the SQL-Editor, and analyze the existing data-structure. Create furthermore an ERD, that describes the existing data-structure in the Crow's Foot Notation.

Suggested approach

  1. We beginn the diagramm by identifying the entities. these are tables without any foreign keys:
    • Customers
    • Categories
    • Employees
    • Shippers
    • Suppliers
  2. Then we determine the attributes and the data-types of each entity (-table).
  3. We continue with the analysis of the relations. These are tables, which have foreign keys in their attribute list.
    • Orders
    • OrderDetails
    • Products
  4. Finally, we connect the tables with each other in the right fashion and determine the cardinalities (1:1, 1:n, n:m)

Solution

Vocabulary

English German
prerequisite Grundvoraussetzung
given gegebene, vorausgesetzt
to determine bestimmen
suggested approach Vorgehensvorschlag

Volkan Demir