COMPSCI 186 Study Guide - Midterm Guide: Relational Calculus, Referential Integrity, Foreign Key
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Question 1 [3 parts, 20 points total]: data models: (10 points) draw a (simple) e-r diagram that results in a primary key/foreign key constraint to be created between tables. Please state specifically which operations on which relations can cause problems: (5 points) consider a database of employees in which we need to record information about employees" addresses. Name one condition which would cause you to make address an entity set of its own rather than an attribute of the employee entity set. Question 2 [3 parts, 15 points total]: pure relational languages. Consider the following schema for an airline database (primary key attributes are in bold): Express the following queries in one of (your choice): relational algebra or relational calculus. 5/12/2006 8:23 pm: (5 points) find the flight_num and date of all flights for which there are no reservations. file:///c:/documents%20and%20settings/jason%20raftery/desktop/r Question 3 [4 parts, 25 points total]: sql.
