index.md

API back-end related

Basic Data Structure

Data Structure Requirement

base on the requirement, the object structure are as below :

Departments( DeptID, DeptName, Location )

Courses( CourseID, Title, Level )

Offer( DeptID, CourseID, Year, ClassSize, AvailablePlaces )

Students( StudentID, StuName, DOB )

Enrolled( StudentID, Year, CourseID, EnrolDate );

Data Dependecy

Consider the requirement and the relation of data structure.
It show Offer have direct relationship to Department and Course, by the DeptID and CourseID. However, there are no direct relation bewteen Department and Course .

While the Student model have direct bonding with Enrolled, by the StudentID, while it also linked to Year , CourseID that having similar variables to Courses and Offer

Therefore, the model relationship can draft as below:

Draft 1

Department Object

// Department 
Department  = {
    _id : String<object_id>,
    DeptID: String,
    DeptName: String,
    Location: String,
    // Course Obj
    Courses: [{
        _id : String<object_id>,
        CourseID: String,
        Title: String,
        Level: Number,
        // Offer Obj
        Offers: [{ 
            _id : String<object_id>,
            Year: Number,
            ClassSize: Number,
            AvailablePlaces: Number
        }] 
    }], 
}

Student Object

// Student Object
Student = {
    _id : String<object_id>,
    StudentID: String,
    StudentName: String,
    DOB: Date,
    // Enrolled Obj
    Enrolled: [{
    _id : String<object_id>,
    CourseID : String,
        Year : String,
        EnrollDate: Date
    }] 
}

Draft 2

Department Object

// Department 
Department  = {
    _id : String<object_id>,
    DeptID: String,
    DeptName: String,
    Location: String,
}

Course-Offer

// Course Obj
Courses={
    _id : String<object_id>,
    DepartmentId : String<department.obj_id>,
    CourseID: String,
    Title: String,
    Level: Number,
    Offers:[ String<offer.obj_id>]
}

Offer-Enrolled

Offers = { 
    _id : String<object_id>,
    Year: Number,
    ClassSize: Number,
    Enrolled : [{
        EnrollDate : Date,
        StudentID : String<student.obj_id>,
    }]
}

Student Object

Student = {
    _id : String<object_id>,
    StudentID: String,
    StudentName: String,
    DOB: Date,
}

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Draft 1 is based on the Department-Course-Offer and Student-Enrolled these relationship, to build the emmbedded document
while Draft 2 is based on the Department, Course-Offer, Offer-Enrolled , Student as the reference collection

Although Draft 1's Data is partrialy replicated, but consider the future use-case in Web Application and mobile application, keeping in same document may less