2. I have a relational database schema: Professor= (Professorld\' name, Deptid,

Question

2. I have a relational database schema: Professor= (Professorld' name, Deptid, password, address) Transcript = Studentld. CrsCode. Semester, Grade) Student (Studentld, name, DeptId, year, address) CourseOfferings = (CrsCode, Semester) Course = (CrsCode. CrsTitle, CrsDescription) Teaches Professorld. CrsCode, Semester) Write out the relational algebra for the following queries. 1). Find the semesters when course *operating systems' was offered. 2) Find the names and Deptld of all professors who taught in spring 2010.

Explanation / Answer

Hi.. I have written querries for the above.

1. Find the semester when course 'opertaing systems' was offered?

Ans: select a.Semester from Transcript a,Course b where a.CrsCode=b.CrsCode and b.CrsTitle='Operating Systems';

2. find the names and departments id of all professors who taught in spring 2010.

Ans: select p.name,p.DeptId from Professor p, Teaches T where p.ProfessorId=T.ProfessorId and T.CrsCode in (select CrsCode from Course where CrsTitle='Spring 2010' )

Please check the querries and let me know any issues. Thank you. All the best.

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