Creating test data for custom parent object and child object in test class

Question

I am writing test class where I need to create test data for standard case object object and parent object for a custom field in case object. When I do the test run it is giving error at the statement where Case object is associated to parent object

Case is linked to BuildingPermit1 with PermitName field. Please help.

private static Contact Contact1;
private static Case Case1;
private static Building_Permit__c  BuildingPermit;

    //create account
    Account1 = new Account();
    Account1.Name = 'Test Company';
    insert Account1;

    //create Contact
   Contact1 = new Contact();
    Contact1.FirstName = 'Testname';
    Contact1.LastName = 'TLname';
    Contact1.Phone = '6667897867';
    Contact1.Email = '[email protected]';


    //create building permit
    Buildingpermit1 = new Building_permit__c();
       Buildingpermit1.permit_name__c = 'testPermit’;
    insert Buildingpermit1;   

   Case1 = new Case();        
   Case1.Origin = 'Phone';
    Case1.Status = 'New';
   Case1.ContactId = mainContact.Id;
   Case1.Subject = 'test subject';
   Case1.Description = 'test desc';
    if (buildingpermit1.Id != null)
  {
  Case1.Buildingpermit1= Buildingpermit1.Id;  //This is the statement where   
                                               //error shows up
  }
    Insert Case1;

Answer 1

You need to use the API name for the field:

Case1.Permit_Name__c = Buildingpermit1.Id;