Is the relation between Patient_inforamtion and Signs classes,

Added on - 16 Sep 2019

  • 2

    pages

  • 505

    words

  • 108

    views

  • 0

    downloads

Showing pages 1 to 1 of 2 pages
1.Is the relation between Patient_inforamtion and Signs classes, is a One-to-many andmandatory. Because the patient has zero or more signs and also one signs belong to zero ormultiple patients. My question, is the above relationship correct and explain what we want?Answer: a person will only be a patient if he or she has one or more signs. If they do nothave any signs, why would their information be registered as a patient. Rest I havecorrected. You are right that a sign may belong to zero or more patients.2.Can you please explain, why are there a composition relationship between Signs andSign_Recommendation classes?Answer: this is a composition because sign_recomendation class cannot exist independently.Since you have created both recommendation_id and sign _id as a primary key togetherhence they cannot hold null values. If they would have been just foreign keys, orsigns_recommendation table would not have been there, then we would have created anaggregation or association relationship.3.Can you please explain, why are there a composition relationship between Recommendationand Sign_Recommendation classes?Answer: this is a composition because sign_recomendation class cannot exist independently.Since you have created both recommendation_id and sign _id as a primary key togetherhence they cannot hold null values. If they would have been just foreign keys, orsigns_recommendation table would not have been there, then we would have created anaggregation or association relationship.4.Why the black diamond to (or next to) Signs and Recommendation classes?Answer: diamond is black because of composition relationship. They both are container/composite classes. Please check your notes5.Can you please explain the reason for choosing the relation between theSign_Recommendation and Recommendation classes?Answer: due to dependency between them. Since signs are there hence recommendationsare there. But the same recommendation can be used for one or more signs.You can say that I have assumed that each sign exists in the database must have arecommendation for it. And each sign may have one or more recommendation or eachrecommendation can be associated with one or more signs.6.Can you please explain the reason for choosing the relation between theSign_Recommendation and Signs classes?Answer: same as 5.7.What the target of Main window? Does the Main window class or not?
desklib-logo
You’re reading a preview
card-image

To View Complete Document

Become a Desklib Library Member.
Subscribe to our plans

Unlock This Document