title: Group by a column then Add each group to datatable then into a dataset
body: <p>what would be the best approach to such thing?</p>
  
  <p>so here is my Datatable</p>
  
  <pre><code>╔═══════════════╦═══════════════╦═══════════════╗
  ║ Product Name  ║ Product Price ║ Product Group ║
  ╠═══════════════╬═══════════════╬═══════════════╣
  ║ Skirt Red     ║            99 ║             1 ║
  ║ Jeans Blue    ║            49 ║             2 ║
  ║ Jeans Black   ║            49 ║             2 ║
  ║ Skirt Blue    ║            99 ║             1 ║
  ║ T-shirt White ║            20 ║             3 ║
  ║ T-shirt Green ║            20 ║             3 ║
  ║ Jeans Grey    ║            49 ║             2 ║
  ╚═══════════════╩═══════════════╩═══════════════╝
  </code></pre>
  
  <p>i will group this datatable by the product group column using LINQ to produce the following groups</p>
  
  <pre><code>Group #1
      ╔═══════════════╦═══════════════╦
      ║ Product Name  ║ Product Price ║ 
      ╠═══════════════╬═══════════════╬
      ║ Skirt Red     ║            99 ║             
      ║ Skirt Blue    ║            99 ║             
      ╚═══════════════╩═══════════════╩
  
  Group #2
          ╔═══════════════╦═══════════════╦
          ║ Product Name  ║ Product Price ║ 
          ╠═══════════════╬═══════════════╬
          ║ Jeans Blue    ║            49 ║             
          ║ Jeans Black   ║            49 ║ 
          ║ Jeans Grey    ║            49 ║
          ╚═══════════════╩═══════════════╩
  Group #3
          ╔═══════════════╦═══════════════╦
          ║ Product Name  ║ Product Price ║ 
          ╠═══════════════╬═══════════════╬
          ║ T-Shirt White ║            20 ║             
          ║ T-Shirt Green ║            20 ║ 
          ╚═══════════════╩═══════════════╩
  </code></pre>
  
  <p>now the questions are </p>
  
  <ol>
  <li>how do i group by the Product group column using LINQ (Done)</li>
  <li>how do i remove the Product group column from the resulted group?</li>
  <li>how do i add each group to a seperate datatable and then add all 
  tables to single dataset?(Done)</li>
  <li>suppose there were columns that i dont want to show in the resulted
  group, how can i hide them?</li>
  </ol>
  
  <p>here is what I've tried so far</p>
  
  <pre><code>    Dim ds As New DataSet
      Dim query = From r In bookedorders Group By key = r.Field(Of Integer)("productgroup") Into Group
      For Each grp In query
          Dim x As New DataTable
          x = grp.Group.CopyToDataTable()
          ds.Tables.Add(x)
      Next
  </code></pre>
  
  <p>now this is working except i am not sure how to select specific columns, like i don't want to show all columns in the resulted datatables</p>