Implement One-To-One Relationship in C# Class

In the previous article we saw how to implement a One-To-Many relationship a in C# class. You can find it here:

Implement one to many relationship in C# class.

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.

Implement One to One relationship in Csharp class

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.

Implement One to One relationship in Csharp class1

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.