Joining Multiple Data-Sources Using "Concat" Key in LINQ: Part 7

This is seventh part of the "LINQ" series of articles that I have started from here. In the last article we explored how to filter, order, group and join in LINQ. Now, in this article we will take a look at doing joins using Concat key in a LINQ query.

Assume we have the following data source information:

Student.cs

class Student

{

public int ID { get; set; }

public string Name { get; set; }

public string Address { get; set; }

public List<int> Marks { get; set; }

}

Teacher.cs

class Teacher

{

public int ID { get; set; }

public string Name { get; set; }

public string Address { get; set; }

}

Program.cs

//DataSource1

List<Student> students = new List<Student>()

{

new Student { ID=1, Name="Abhimanyu K Vatsa", Address="Bokaro", Marks= new List<int> {97, 92, 81, 90}},

new Student { ID=2, Name="Deepak Kumar", Address="Dhanbad", Marks= new List<int> {70, 56, 87, 69}},

new Student { ID=3, Name="Mohit Kumar", Address="Dhanbad", Marks= new List<int> {78, 76, 81, 56}},

new Student { ID=4, Name="Geeta K", Address="Bokaro", Marks= new List<int> {95, 81, 54, 67}}

};

//DataSource2

List<Teacher> teachers = new List<Teacher>()

{

new Teacher {ID=1, Name="Ranjeet Kumar", Address = "Bokaro"},

new Teacher {ID=2, Name="Gopal Chandra", Address = "Dhanbad"}

};

And I want to select those Student's names and Teachers from "Bokaro" by Concat. So, we can use a LINQ query to create an output sequence that contains elements from more than one input sequence. Here it is:

//Query using Concat

var query = (from student in students

where student.Address == "Bokaro"

select student.Name)

.Concat(from teacher in teachers

where teacher.Address == "Bokaro"

select teacher.Name);

And the output is:

Abhimanyu K Vatsa

Geeta K

Ranjeet Kumar

Remember, this also can be done using join, that we already saw in one of the previous articles.

I hope you will find it useful. Thanks for reading.