query - Assumption:Professor alone cannot teach a...

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Name ISBN Publisher Name Has Book Publisher ISBN Publisher Name Has Book Name ISBN Publisher Assumption:Professor alone cannot teach a section.He has to team up with a GTA for teaching. Entity sets: Professor GTA Student Class Section Relationship Sets and their multiplicity: 1) Entity set “Class” has certain prerequisite classes. So relationship set “prerequisite” is used to represent the relationship. Class may have a prerequisite or may not have a prerequisite. A prerequisite class must have at least one class for which it is a prerequisite. So it is denoted by participation constaint. There is no limit for the number of classes for which a class can be a prerequisite so no other constraints are required. 2) Relationship set has is between entity sets Class and section. Section is a weak entity. A section should have a single owner which is entity class. The class and section entity participate in one to many relationship set.The entity set ‘section’ has total participatin with the identifying relationship set ‘has’ 3) The relationship set ‘enrolls in’ is defined between entities student and section.No special condition has been mentioned regarding student and section. 4) Professor works with GTA: The relationship set ‘works with’ is defined between entities GTA and professor. 5) The relationship set ‘assignedto' is defined between Aggregation of works with relationship between entity sets professor and GTA and section 6) GTA is a student: Class hierarchy Primary Key: Professor: ssn GTA: ssn (GTA is a student .It gets the same primary key as of student Student :ssn Class: deptname, courseno Section: weak entity :so partial key is secno, semester, year 2)In the above diagram the property that no more than 10 students can wait on a class at the same time cannot be cannot. It can only be implemented in the schema
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3)Reports: 1)List all the professors who are teaching more than one section in the current semester . This report involves the relationship sets ‘works with’ and ‘assignedto’. 2)List all the courses a student has enrolled in and received a grades in the previous two semesters
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This note was uploaded on 04/18/2011 for the course INFS 614 taught by Professor Prof during the Spring '11 term at GWU.

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query - Assumption:Professor alone cannot teach a...

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