How can I properly return a json result which includes two or more tables?

See more:

C#

ASP.NET

I would like to return json data from my controller but the error i get is "a circular reference was detected while serializing an object of type".

So far i can only return data from only one table called "Projects" but when i try to include my look up table "ProjectTypes" i get the circular reference. if there is a way to return data of Projects and its correct Project Type please kindly assist me.

What I have tried:

This is what i have tried but .Include does work with return json.

public JsonResult getProjects()
{
    bool proxyCreation = dc.Configuration.ProxyCreationEnabled;
    try
    {
        //set ProxyCreation to false
        dc.Configuration.ProxyCreationEnabled = false;

        var projects = dc.Projects.Include(p => p.ProjectType);

        return Json(projects.ToList(), "application/json", System.Text.Encoding.UTF8, JsonRequestBehavior.AllowGet);

    }

    catch (Exception ex)
    {
        Response.StatusCode = (int)HttpStatusCode.BadRequest;
        return Json(ex.Message);
    }

    finally
    {
        //restore ProxyCreation to its original state
        dc.Configuration.ProxyCreationEnabled = proxyCreation;
    }
}

Below are my two classes

public partial class Project
    {
        public int ProjectID { get; set; }
        public string Description { get; set; }
        public System.DateTime StartDate { get; set; }
        public Nullable<System.DateTime> EndDate { get; set; }
        public System.DateTime ProjectedEndDate { get; set; }
        public int ProjectTypeID { get; set; }

        public virtual ProjectType ProjectType { get; set; }
    }

 public partial class ProjectType
    {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public ProjectType()
        {
            this.Projects = new HashSet<Project>();
        }

        public int ProjectTypeID { get; set; }
        public string Description { get; set; }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Project> Projects { get; set; }
    }