1 Class Agenda – 09/20/2011  Answer questions about exam  Evaluate database design homework  Review database design homework for syntax and logic  Finish class ERD exercise from 9/13??  Demonstrate Visio

2 Evaluate design homework  Break into groups as assigned  Everyone takes out a sheet of paper  Exchange assignments  Put your name (as the “evaluator”)at the top of the sheet of paper  Evaluate the syntax and logic of the designs  Make your comments on the sheet of paper

3 “Syntax” Database Modeling Issues  Does the diagram contain entities, attributes, primary keys and relationships?  Is it structured using the modeling format discussed in this class? (see next slide for modeling format)  Does each entity have a primary key? Is the primary key labeled as a primary key?  Is each relationship labeled with a verb or verb phrase?  Does each relationship have a foreign key? Is the foreign key labeled as a foreign key?

5 “Logic” Database Modeling Issues  Is all necessary data represented on the model? What’s missing?  Is the data grouped correctly with the appropriate entity?  Does each entity have a primary key that will yield a unique value for each row?  Is the primary key reasonable (not too many not too few attributes?)  Are the entities related accurately?  Are the cardinalities of the relationships accurate?  Are there any M:N relationships?  Are the foreign keys accurate and is each placed in the correct entity to sustain a relationship?  Will the design yield redundant data?