db-design

Thanks this info was really helpful! I used a webs… Unknown - Jun 2, 2014Thanks this info was really helpful! I used a website called Lucidchart to find er diagram examples and it was really easy to understand. If you use diagrams often you should check it out! Yes its a good and online option. For offline (and online) option, we can also use Microsoft Visio, which is equally good. [Read More]

Problem Draw an entity-relationship diagram for a database with companies, people, and professionals (people who work for companies). Solution Entities: Company: companyID, companyName, companyLocation, ect People: peopleID, name, gender, age, etc Professional: professionalID , FK to People, degree, work experience Relations: People ISA Professionl: 1:1 Professional WORKS Company: N:1 People who work for companies are Professionals. So there is an ISA (is a) relationship between People and Professionals (or we could say that a Professional is derived from People). [Read More]