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Relational Algebra

Relational Algebra. Divide Examples Query Problems. Divide Example. T1. T2. What is the result of the following divide expression?. T1 / T2. Divide Example. CoursesCompleted. DatabaseCourseCodes. Divide Example. What is the result of the following query?

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Relational Algebra

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  1. Relational Algebra • Divide Examples • Query Problems

  2. Divide Example T1 T2

  3. What is the result of the following divide expression? T1 / T2

  4. Divide Example CoursesCompleted DatabaseCourseCodes

  5. Divide Example • What is the result of the following query? • CoursesCompleted / DatabaseCourses • What question could the above expression be an answer to?

  6. Query Problems • Find the faculty (all attributes) in the computer science department (DeptID CS) • Find the names of faculty in the computer science department • Find the capacity of classrooms with more than 100 seats • Find the names of courses that have a prerequisite of CS 220

  7. Query Problems • Find the names of courses offered in the Spring • Find the names of students who received an Incomplete in Fall 2012. • Find the names of courses that have never been taught. • Find the names of faculty who taught a class in Spring of 2012 • Find the names of students who have passed all prerequisites for CS 442

  8. Query Problems • Find the names of students who have passed all computer science courses. • Find the names of faculty who taught a courses that is a prerequisite for MTH 444 in Fall 2012. • Find the names of faculty who taught all courses that are prerequisites for MTH 444 in Fall 2012.

  9. Query Problems • Find the class(es) with the smallest enrollment in Spring of 2013. • Find the name(s) of the course(s) worth the most credits

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