DbContext is not giving any data from database - entity-framework

Question

I have two sets of codes. The first one doesn't give me the list of data but the second on does. Please see codes below:
First Code:
Model
public class Student
{
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public string Gender { get; set; }
}
DataConnection
public class DataConnection : DbContext
{
public DataConnection()
: base("DefaultConnection")
{
}
public DbSet<Student> Students { get; set; }
}
Interface
public interface IStudent
{
List<Student> StudentList();
void InsertStudent(Student student);
void UpdateStudent(Student student);
Student GetStudentById(int id);
void DeleteStudent(int id);
}
Concrete
readonly DataConnection _context;
public StudentConcrete()
{
_context = new DataConnection();
}
public List<Student> StudentList()
{
var studentList = (from s in _context.Students select s).ToList();
return studentList;
}
Second Code
Concrete
readonly DataConnection _context;
public StudentConcrete()
{
_context = new DataConnection();
}
public List<Student> StudentList()
{
SqlConnection xxx = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString);
var cmd = new SqlCommand("GetAllStudents", xxx);
var da = new SqlDataAdapter(cmd);
var ds = new DataSet();
da.Fill(ds);
if (ds.Tables[0].Rows.Count > 0)
{
return (from DataRow row in ds.Tables[0].Rows
select new Student()
{
Age = Convert.ToInt32(row["Age"]),
FirstName = row["FirstName"].ToString(),
Gender = row["Gender"].ToString(),
LastName = row["LastName"].ToString()
}).ToList();
}
else
{
return null;
}
}
I would like to get the data using the first code but I don't know where I get it wrong. My SP is just to get the students.

Answer 1

I suspected that maybe you are retrieving the records from another table somehow. Would you try to add Table attribute for Student entity.
using System.ComponentModel.DataAnnotations.Schema;
[Table("Students")]
public class Student
{
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public string Gender { get; set; }
}