title: Remove primary key in datatable
body: <p>is there a way to remove primary key from the datatable Or is there any way to remove the constraints of "PK" first and then remove the column itself?</p>
  
  <p>Thanks!</p>
  
  <p>UPDATED:</p>
  
  <pre><code> dtTable.Columns.Add(new System.Data.DataColumn("PRIMARY_KEY", typeof(System.Int32)));
   dtTable.PrimaryKey = new DataColumn[1] { dtTable.Columns["PRIMARY_KEY"] }; // throws an error
   dtTable.Columns["PRIMARY_KEY"].AutoIncrement = true;
  </code></pre>