DirtBike Order Database– ER Diagram Prepared by Dustin Withee Fall 2012

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

Entity ClassPrimary Key CustomerCustomerID OrderOrderID ProductProductID DistributorDistID Step 1: Define Entity Classes and Primary Keys Business Rules Each customer can have one order Each customer can have multiple orders Customers can be in your database and not have any orders Each order is made by a single customer Orders may have multiple products Each product has to have a distributor Orders cannot be blank but have at least one product Products can be listed in your database but not purchased The same product can be purchased through many orders A distributor can supply multiple products A distributor has to supply at least one product

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

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

Step 3: Define Fields for each Relationship CustomerIdLastNameFirstNameAddressCityStateZipPhone Customer OrderIdCustomerID Order OrderIdProductIDQuantity Detailed Orders DistributorIdDistributor ProductIdProductNameManufacturerColorMSRPIgnitionWeightQOHDistID Product

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