1. DirtBike Order Database– ER Diagram Prepared by Dyan Strausheim Fall 2012

2. Step 1: Define Entity Classes and Primary Keys Step 2: Define Relationships Among Entity Classes Step 3: Define Fields for each Relationship Step 4: Create Database Designing Databases with Entity Relationship Diagrams

3. Entity ClassPrimary Key CustomerCustomer ID OrderOrder ID ProductProduct ID DistributorDistributor ID Step 1: Define Entity Classes and Primary Keys Business Rules Each customer can have one order Each customer can have multiple orders A customer can be in your database without any orders Each order is made by a single customer Orders cannot be blank but have to have at least one product Orders may have multiple products The same product could be purchased through many orders Products can be listed in your database but not purchased A distributor can supply multiple products Each distributor has to supply at least one product Each product must have a distributor

4. E-R Diagrams Use 5 symbols 1.Rectangle – entity class 2.Dotted line – relationship 3.| - single relationship 4.0 – zero/optional relationship 5.Crow’s foot (  ) – multiple relationship

5. PRODUCT CUSTOMER ORDER Step 2: Define Relationships Among Entity Classes DISTRIBUTOR Detailed Orders

6. Step 3: Define Fields for each Relationship Customer IDLast NameFirst NameAddressCityStateZipPhone Customer Order IDCustomer ID Order Date Order Product IDProduct NameManufacturerColorMSRPIgnitionWeightQOHDistributor ID Product Distributor IDDistributor Order IDProduct IDQuantity Detailed Orders

7. Step 4: Create Database (At this point we will begin working with our DBMS system, which will be Microsoft Access)