using (var context = new TestDBEntities())
{
    var query = from p in context.Parents
                where p.Name == "Lingzhi"
                select p;

    ObjectQuery<Parent> parents = query as ObjectQuery<Parent>;
    if (parents != null)
    {
        string sql = parents.ToTraceString();
    }
}

            LckDbContext ef = new LckDbContext();
            var personInfo = from a in ef.Persons.Include("Photo")
                             select a;         
            Console.WriteLine(personInfo.ToString());