Users register into the system and first share some information about themselves

Question

Users register into the system and first share some information about themselves: their nickname, their first and last name, their year of birth, the city and the suburb that they live in. Then they are asked to write about themselves in their profile: what sort of job they do, something about their family, and what they like to watch on TV. If they wish, they can also upload one video introducing themselves, which will be stored on the system at a specific location. They should include the video title and a description. The system will also record the duration of the video. The filetype must be either AVI, MOV, MP4, WMV or FLV.

Finally, they are invited to share about their illness(es): they choose their condition from a pre-defined set of illnesses, noting how long they have experienced the illness and to what degree (using a 5-point scale, 1 being low and 5 being extreme). For each illness, they also indicate which health practitioner they are seeing on a regular basis and must provide the practitioners contact information (name, physical address, up to three contact phone numbers). Health practitioners can be doctors, physiotherapists or dieticians. If a user is treated by a practitioner who is already in the database, they may simply confirm the existing contact information already in the database.

Users can have one mentor, and can be a mentor to any number of other users. Users can also write posts on a message board within the system. When users post a message, the content, date and time of the message is also recorded. Other users can comment on posts and the time and date of the comments are recorded in the system. This information can then be used by the application alongside profile information, connections and mentors/mentees, in order to offer better recommendations.

Task 2:

Derive a Relational Model from the conceptual schema you provided in Task 1 (it should match exactly).

List all the relations derived from the entity types of the ERD, and their initial attributes. (1 mark)

For each relationship type in the ERD justify whether it leads to a new relation, a new attribute in a relation derived from an entity type, or to a merger of two relations derived from two entity types. (1 mark)

List all the relations in the final relational model, and all their attributes (1 mark)

List all the constraints included in the conceptual schema in addition to the relevant primary keys and foreign keys. (2 marks)

Users Name tPK) firstName lastName nickname yearofBirth Posts O..n Uploads 1..1 Content PK) Comments Date Mentors City suburb name Profile job family tvProgram 1..n Video Title (PK) duration description fileType 0..1 Has 1..n IlInesses doctorName(PK) degree(1-5) condition duration Health Practioners doctorNamePK) address phoneNumber Treated by 1.n

Explanation / Answer

If you have any doubts, please give me comment...

Users(Name, firstName, lastName, nickName, yearofBirth, City, suburb,name, Profile, job, family, tvProgram, MentorName, PostContent);

Posts(Content, Comments, Date);

illnesses(doctorName, degree, condition, duration);

Video(Title, duration, description, fileType);

HealthPractioners(doctorName, address, phoneNumber);

UsersHasIllnesses(UserName, doctorName, VideoTitle);

Note:

Underline indicates Primary keys

Italics indicates Foregin keys

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