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This is a question which consist of a scenario with a given E-R diagram that need to be corrected by applying the given instructiors in the scenario and i have posted it here as points and i have attached my answer. i really hope someone could tell me if i hava mistake on it or not.


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A center called ITARD do employing for Researchers(R), Research Assistants (RAs) and Administrators (A). The information that should kept for each employee are [ FName , MName , LName , Bdate , Gender , Address , Phone , Mobile , date of joined , date of left]

The information that should kept for each Project are [ Title, its description , start date , planned end date , actual end date , total planned budget , the PI ( principle investigator) ,The RAs and whom each is assigned]

These are the requirement that should be represented in the E-R diagram

1-At the same Time, Each researcher may work on one or more active research projects.

2- A researcher not working on any active research projects may engage in any number of unsponsored research project with or without collaboration from the other researchers and in each case , they are not aided by any RA.

3-Researchers can collaborate on research projects, but there must be one PI (principle Investigator) designed each project.

4-Each Research Assistant (RA) is assigned to work on one or more projects.

5-Each (RA) is supervised be exactly one researcher for each research project the RA works on.

6-Since (RAs) are hired on research projects, no RA can be left without assigned tasks in one or more research projects.

7-Each project must be administered by one Administrator. Additionally, each administrator is supervised by one supervisor (another administrator)

i have solved this questions and I need to be sure of my solution if there is any mistake, if someone discoved mistakes please replay .

please take a look on the photo of the ERD below.

http://i.imgur.com/LV1ry.png

regards

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