Data Mapping (ERD)

The diagram uses standard ER notation where: Rectangles represent Entities (main objects/tables). Ellipses represent Attributes (properties/columns of the entities). Diamonds represent Relationships (associations between entities). 1. Entities (Rectangles) sales offices: Represents the physical locations where sales operations occur. employees: Represents the personnel working within the organization. property: Represents the physical real estate assets being managed or listed. owners: Represents the individuals or entities that possess the properties. 🔗 Relationships and Cardinality The diagram shows two primary relationships: 1. sales offices and employees Relationship: assigned (Employees are assigned to sales offices). Cardinality: The crow's foot symbol (three lines) is on the employees side, indicating many employees. A single line on the sales offices side usually indicates one. Interpretation: This is a One-to-Many (1:N) relationship. One sales office can have many employees assigned to it, but an employee is assigned to only one sales office. 2. sales offices and property Relationship: lists (Sales offices list properties). Cardinality: The diagram doesn't explicitly show the cardinality on the property side, but the symbol on the sales offices side suggests one sales office. Interpretation (Likely): It's likely a One-to-Many (1:N) relationship, where one sales office lists many properties. 3. property and owners Relationship: Relationship (Properties are related to owners, likely owned by them). Cardinality: The diagram doesn't explicitly show the cardinality on either side. Interpretation (Likely): This could be One-to-One (1:1) (one property has one owner) or One-to-Many (1:N) (one owner has many properties). 📋 Attributes (Ellipses) sales offices: Location, Office_Number (likely the primary key). employees: Employee_ID (likely the primary key), Employee_Name. owners: Owner_ID (likely the primary key), Owner_Name. property: Property_ID (likely the primary key), City, Address, State, Zip_Code, and a redundant (Location) attribute.