1. A company database needs to store information about employees (identified by SIN, with salary and phone as attributes), departments (identified by DID, with dname and budget as attributes), and children of employees (with name and age as attributes). Employees work in departments; each department is managed by an employee; a child must be identified uniquely by name when the parent (who is an employee; assume that only one parent works for the company) is known. We are not interested in information about a child once the parent leaves the company.

Draw an ER diagram using Crows Foot notation that captures this information.

Consider the ER diagram of online sales system above. Based on the diagram answer the questions below,

a) Based on the ER Diagram, determine the Foreign Key in the Product Table. Just mention the name of the attribute that could be the Foreign Key.

b) Mention the relationship between the Order and Customer Entities. You can use the following:

1:1, 1:M, M:1, 0:1, 1:0, M:0, 0:M

c) Is there a direct relationship that exists between Store and Customer entities? Answer Yes/No?

d) Which of the 4 Entities mention in the diagram can have a recursive relationship?

e) If a new entity Order_Details is introduced, will it be a strong entity or weak entity? If it is a weak entity, then mention its type?

ER Diagram of Online Sales System Product PK ProductID OrderID DepartmentID Product Name Price Cutomer CustomerID Order OrderID PK Full Name FK1 FK2 CustomerID StoreID Sales Amount Date Time Store PO ---HR StorelD Store Name ER Diagram of Online Sales System Product PK ProductID OrderID DepartmentID Product Name Price Cutomer CustomerID Order OrderID PK Full Name FK1 FK2 CustomerID StoreID Sales Amount Date Time Store PO ---HR StorelD Store Name