Q4. Draw a logical relational data model for the proposed system. Be sure to include primary and foreign keys in your model. (15 marks)

The Pergola Man has many customers.  Each customer has a unique customer number

(the name, address, phone and email of each customer is also stored).  Customer credit card details are not stored

in the system. The Pergola man can construct two types of building, pergolas

and gazebos.  Each quotation has a unique

identifier, quotation number. Each quotation contains the customer details, the

construction type and description as well as a list of the materials used to

construct the pergola or gazebo.  The

quotation also lists the number of hours spent on the job and the cost per

hour.  The cost per hour can change over

time.