Consider building a database for a shopping mall with requirements as follows:

 Each product of the shopping mall has a unique project No, and also has a name, a supplier name, a category, a purchase price and a selling price.

 Products need to be supplied from suppliers. Each product has one supplier, but a supplier may supply many products for the shopping mall.

 Each supplier has a supplier name and address.

 A purchase order for product from a supplier has a unique order No, and a date. The order specifies one or more products and their quantities required for a product.

 A sales order for product to customers has a unique order No, and a date. The order specifies one or more products and their quantities required for a product

 The shopping mall has warehouses. Each warehouse has a warehouse number, an address and a contact phone number. Each warehouse has shelves to store products. Each shelf has a shelf-number and a capacity. The shelf number is not unique across warehouses, but it is unique within each warehouse. For example, warehouse A has only one shelf numbered as 14 and warehouse B may also have one shelf numbered as 14.

 Products are sent to warehouses for storage. For the ease of product distribution, the shopping mall records the warehouses and shelf-numbers for storing each product, together with the quantity for the product.

 Each customer of the shopping mall is identified by a customer ID.

 Information about shopping mall employees includes a unique employee ID, and his/her name and position.

 Some customers are VIP customers who are identified by a membership number and have a name and contact number. While a VIP customer is serviced by one service specialist (who is an employee). A service specialist cares for several VIP customers.

 Customers can place multiple purchase orders. Each order is described by the date of the order and quantity of the clothes s/he orders. VIP customers can receive a discount rate on their purchase.

Based on the information you gathered, model the activities of the shopping mall and present your model as an Entity-Relationship (ER) diagram. In your ER diagram, you must properly denote all applicable concepts, including weak or strong entities, keys, composite or multi-valued attributes; relationships and their cardinality and participation constraints. You must use UML notation and the diagramming tool LucidChart to draw your diagram. Your diagram must be drawn to a high standard with minimal clutter, following the standard demonstrated in the course notes and LucidChart activity sheet. 

Notes: 

1. You may add new primary key attributes if you believe it is appropriate to do so. 

2. Do not add other details that are not described, such as extra attributes and entities that are not mentioned above. 

3. Carefully state any assumptions that you make.