1 - Dr. Stefan Brass February 18, 2000 School of...

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Unformatted text preview: Dr. Stefan Brass February 18, 2000 School of Information Sciences University of Pittsburgh INFSCI 2710 Database Management Solution to Example Midterm Exam II Exercise 1 (ER Design) 12 Points This exercise was a bit difficult because the application is from German canteens/cafeterias for students. The American system is different. I will try to use other examples in future which are better known. Component C Name H H H Recipe Ingredient I Name Calories H H H (0 , * ) H H H H contains H H H H (0 , * ) Quantity J J J t,d Main Dish Side Dish H H H H H H (0 , * ) @ @ @ part of @ @ @ (1 , 1) (0 , * ) @ @ @ part of @ @ @ (0 , * ) Menu M No Q Q Q M Name Price Sales Date Num Sold H H H (0 , * ) H H H H H H H H results in H H H H H H H H You do not need to use subclasses for main dishes and side dishes. If you use an attribute Type, you must add a constraint that every Menu contains only one main dish. INFSCI 2710 Database Management Solution to Midterm Exam (Summer 1999) 2 You do not need to use a weak entity for the sales. You could use an entity for Date and put Num Sold as an attribute to the relationship offered on between Menu and Date....
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1 - Dr. Stefan Brass February 18, 2000 School of...

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