Loop through Master-Detail Records using LINQ

Here’s an example of how to loop through Master-Detail Records using LINQ. I have taken the example of one Department containing multiple Employees. The example is taken only for the purpose of understanding and does not cover all scenarios.

class Program
{
    static void Main(string[] args)
    {
       

        var lst = from d in dept
                    from e in dept.emp
                    select new { d, e };
        foreach (var rec in lst)
        {
            Console.WriteLine("{0}, {1}", rec.d.DeptNm, rec.e.EmpNm);
        }
        Console.ReadLine();
    }
}

class Department
{
    public int DeptID { get; set; }
    public string DeptNm { get; set; }
    public IList<Employees> emp = new List<Employees>();
}

class Employees
{
    public int EmpID { get; set; }
    public string EmpNm { get; set; }
    public string Address { get; set; }
}

As you can see, ‘dept’ is an object of class Department. The Department class contains a collection of Employees.

public IList<Employees> emp = new List<Employees>();

To loop through each Employees in a Department, we make use of the following LINQ Expression

var lst = from d in dept
            from e in dept.emp
            select new { d, e };
foreach (var rec in lst)
{
    Console.WriteLine("{0}, {1}", rec.d.DeptNm, rec.e.EmpNm);
}

The list prints the Department Name and the Employees in it.