ASP.NET

private void BindData()<br />
		{<br />
			strPartNumberInputReference = txtPartNumberInput.Text			 <br />
			string SQLString = "SELECT p.PartNumber, p.ID as ptID, pt.description, dd.DrawingNumber, dd.DrawingRevision, dd.DwgPath FROM parts p INNER JOIN PartTypes pt on pt.ID =p.PartTypeID LEFT JOIN DraftingData dd on dd.PartID = p.ID WHERE p.PartNumber = @PartID;SELECT w.weight, wt.Description AS wtDescription, p.PartNumber from weights w INNER JOIN weighttypes wt on wt.ID = w.weighttypeid INNER JOIN Parts p on w.PartID = p.ID WHERE p.PartNumber = @PartID;SELECT c.cost, p.PartNumber, ct.Description AS ctDescription from Costs c INNER JOIN Parts p ON c.PartID = p.Id INNER JOIN CostTypes ct on ct.Id = c.CostTypeID WHERE p.PartNumber = @PartID; SELECT s.SubPartID, s.Quantity, s.Sequence, p.PartNumber FROM SubParts s INNER JOIN Parts p ON s.PartID = p.Id "; <br />
			SqlCommand cmd = new SqlCommand();<br />
			cmd.Connection = new SqlConnection(strConnectSQL);<br />
			cmd.CommandText = SQLString;<br />
			cmd.Parameters.Add ("@PartID", strPartNumberInputReference);<br />
			SqlDataAdapter adapter = new SqlDataAdapter(cmd);<br />
			adapter.Fill(ds);<br />
			<br />
			ds.Tables[0].TableName = "Rest";<br />
			ds.Tables[1].TableName = "Weights";<br />
			ds.Tables[2].TableName = "Costs";<br />
			ds.Tables[3].TableName = "Subparts";<br />
<br />
			<br />
			dgParts.DataSource = ds;<br />
			dgParts.DataBind();<br />
			txtPartNumberInput.Text = "";<br />
	<br />
		<br />
		}

private void add_Click(object sender, System.EventArgs e)<br />
		{<br />
			DataTable dt2 = ds.Tables["Rest"];<br />
			DataRow row;<br />
			row = dt2.NewRow();<br />
			row.ItemArray = dt2.Rows[0].ItemArray;<br />
			row["PartNumber"]=strPartNumberInputReference = txtPartNumberInput.Text;<br />
			//An invalid data source is being use for Description. A valid data source must implement either IListSource or IEnumerable.<br />
			//row["Description"]=DBNull.Value;<br />
			//row["partTypeID"]=DBNull.Value;<br />
			row["DrawingNumber"]=DBNull.Value;<br />
			row["DrawingRevision"]=DBNull.Value;<br />
			row["DwgPath"]=DBNull.Value;