Join Json Objects in VB.net using Json.NET

Let's say we have two JSON viz.

Employee JSON
--------------
{
  "Employees": {
    "Employee": [
      {
        "DeptId": "111",
        "EmployeeName": "Niladri"
      },
      {
        "DeptId": "222",
        "EmployeeName": "Arina"
      },
      {
        "DeptId": "111",
        "EmployeeName": "Babai"
      },
      {
        "DeptId": "222",
        "EmployeeName": "RNA Team"
      }
    ]
  }
}

and

Department JSON
----------------
{
  "Departments": {
    "Department": [
      {
        "DepartmentName": "HR",
        "Deptid": "111"
      },
      {
        "DepartmentName": "Finance",
        "Deptid": "222"
      }
    ]
  }
}

The objective is to join these two JSON and to find out which Employees belongs to which Department

Imports Newtonsoft.Json
Imports System.Collections.Generic
Imports System.Dynamic
Imports System.Linq

Namespace ConsoleApplication1
	Class Program
		Private Shared Sub Main(args As String())
			Dim empInformation = GetEmpInformation()
			Dim deptInformation = GetDeptInformation()

			'join between  EmpInformation and DeptInformation       


			Dim recordSet = (From emp In empInformationJoin dept In deptInformation On DirectCast(DirectCast(emp, IDictionary(Of String, Object))("DeptId"), String) = DirectCast(DirectCast(dept, IDictionary(Of String, Object))("DeptId"), String)New With { _
				Key .EmployeeName = DirectCast(DirectCast(emp, IDictionary(Of String, Object))("EmployeeName"), String), _
				Key .DepartmentId = DirectCast(DirectCast(emp, IDictionary(Of String, Object))("DeptId"), String), _
				Key .DepartmentName = DirectCast(DirectCast(dept, IDictionary(Of String, Object))("DepartmentName"), String) _
			})

			'print the result
			recordSet.ToList().ForEach(Function(i) Console.WriteLine("Employee {0} belongs to Department {1}", i.EmployeeName, i.DepartmentName))

			Console.ReadKey()
		End Sub

		Private Shared Function GetEmpInformation() As List(Of ExpandoObject)
			Try
				Dim empObj = New List(Of ExpandoObject)()
				Dim source = "{'Employees': {'Employee': [{'DeptId': '111','EmployeeName': 'Niladri'},{'DeptId': '222','EmployeeName': 'Arina'},{'DeptId': '111','EmployeeName': 'Babai'},{'DeptId': '222','EmployeeName': 'RNA Team'}]}}"
				Dim employeeInfo As dynamic = JsonConvert.DeserializeObject(source)

				Dim countRecord = employeeInfo.Employees.Employee.Count

				For i As var = 0 To countRecord - 1
					Dim expandoObj As dynamic = New ExpandoObject()
					expandoObj.DeptId = Convert.ToString(employeeInfo.Employees.Employee(i).DeptId)
					expandoObj.EmployeeName = Convert.ToString(employeeInfo.Employees.Employee(i).EmployeeName)

					empObj.Add(expandoObj)
				Next

				Return empObj
			Catch ex As Exception
				Throw ex
			End Try
		End Function

		Private Shared Function GetDeptInformation() As List(Of ExpandoObject)
			Try
				Dim deptObj = New List(Of ExpandoObject)()
				Dim source = "{'Departments': {'Department': [{'DepartmentName': 'HR','Deptid': '111'},{'DepartmentName': 'Finance','Deptid': '222' }]}}"
				Dim departmentInfo As dynamic = JsonConvert.DeserializeObject(source)

				Dim countRecord = departmentInfo.Departments.Department.Count

				For i As var = 0 To countRecord - 1
					Dim expandoObj As dynamic = New ExpandoObject()
					expandoObj.DeptId = Convert.ToString(departmentInfo.Departments.Department(i).Deptid)
					expandoObj.DepartmentName = Convert.ToString(departmentInfo.Departments.Department(i).DepartmentName)

					deptObj.Add(expandoObj)
				Next

				Return deptObj
			Catch ex As Exception
				Throw ex
			End Try
		End Function
	End Class
End Namespace

In the GetEmpInformation() method, we are converting the Employee Json string into an object by using the JsonConvert.DeserializeObject method, then looping through the record count and preparing the List<ExpandoObject>. The same follows for GetDeptInformation().So now we have both the Employee and Department information (collections) at our hand.The last step is to fire a JOIN using LINQ to find out the matching record.