Implement one to one Relation in c# Classes

In this article we will learn to implement a One-To-One relationship between two classes. As in the previous article, at first we will try to understand the best use of a One-To-One relationship.

There might be a situation where we need to implement a relationship between a student and his registration number. In a university a student has one registration number. Another example of a One-To-One relationship is a happy couple. Ha..Ha.. Ok, then implement an example of a happy couple relationship.

Happy couple relationship

This will show an example of a One-To-One relationship. Have a look at the following code.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Client

{

    class boy

    {

        Girl g = new Girl();

        public string BoyName { get; set; }

        public Girl getSetGirl

        {

            get { return g;}

            set {g = value; }

        }

        public void Print()

        {

            Console.WriteLine("Boy Name:- " + this.BoyName);

            Console.WriteLine("Girl Name:- " + this.getSetGirl.GirlName);

        }

    }

    class Girl

    {

        public string GirlName { get; set; }

    }

    class Program

    {

        static void Main(string[] args)

        {

            Girl a = new Girl();

            a.GirlName = "Rimpa";

            boy b = new boy();

            b.BoyName = "Sourav";

            b.getSetGirl = a;

            b.Print();

            Console.ReadLine();

        }

    }

}

Here is the sample output. 

Student and mark sheet relationship

It is also an example of a One-To-One relationship. Generally one student has one mark (answer) sheet in one examination. Have a look at the following code.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Client

{

    class Student

    {

        public string Name { get; set; }

        public Marksheet GetSetMarksheet { get; set; }

       

        public void Print()

        {

            Console.WriteLine("Name :- " + this.Name);

            Console.WriteLine("Roll :- " + this.GetSetMarksheet.Roll);

            Console.WriteLine("Total Mark:- " + this.GetSetMarksheet.TotalMark);

            Console.WriteLine("Position :- " + this.GetSetMarksheet.Position);

        }

    }

    class Marksheet

    {

        public int Roll { get; set; }

        public int TotalMark { get; set; }

        public int Position { get; set; }

    }

   

    class Program

    {

        static void Main(string[] args)

        {

            Student s = new Student();

            s.Name = "Sourav";

            Marksheet m = new Marksheet();

            m.Roll = 100;

            m.TotalMark = 500;

            m.Position = 10;

            s.GetSetMarksheet = m;

            s.Print();

            Console.ReadLine();

        }

    }

}
Here is sample output.



Conclusion
In this article we learned to implement a One-To-One relationship between C# classes. Hope you have understood the concept. In a future article we will see how to implement a Many-To-One and Many-To-Many relationship between C# classes.