title: Get value from datareader
body: <p>Given below is a sample piece of code I've written in VB.NET.</p>
  
  <pre><code> commandReader.CommandText = "Select stu_id from tbl_students Where stu_id = 845)"
     dr = commandReader.ExecuteReader
     While dr.Read
          var_stu_id = dr!stu_id
          var_stu_id = dr.GetValue(dr.GetOrdinal("stu_id"))
          var_stu_id = dr("stu_id")
          var_stu_id = dr.GetValue("stu_id")
     End While
     dr.Close()
  </code></pre>
  
  <p>There are 4 ways of getting a particular value from a <code>DataReader</code>. I would like to know which is the best method among them(if anyone point out the difference between each of them then it'll be a great help).</p>