Help with JTable

//Constr
purchaseTableModel=new DefaultTableModel(){
			private static final long serialVersionUID = 1L;
 
			public boolean isCellEditable(int row, int column) {
				if(column==3)
				{
					return true;
				}else
				{
					return false;
				}
			}
};
 
 
//call this method in constr which created the table.
private void readPurchaseDetails()
	{
		PreparedStatement stmt=null;
		ResultSet rs=null;
		
		try
		{			
			stmt=conn.prepareStatement("SELECT     RawMaterial.RawMaterialCode, RawMaterial.RawMaterialName, ProductBoughtSupplierDetail.total, " +
					" ProductBoughtSupplier.DiscountAmt,ProductBoughtSupplier.CommissionAmt, Tafsil.TafsilDescription AS [Discount Account]," +
					" Tafsil_1.TafsilDescription AS [Commission Account],Tafsil_2.TafsilDescription AS [Commission To]" +
					" FROM         ProductBoughtSupplier INNER JOIN ProductBoughtSupplierDetail ON " +
					" ProductBoughtSupplier.IncomingID = ProductBoughtSupplierDetail.IncomingID INNER JOIN" +
					" RawMaterial ON ProductBoughtSupplierDetail.RawMaterialID = RawMaterial.RawMaterialID INNER JOIN" +
					" Tafsil ON ProductBoughtSupplier.TafsilID = Tafsil.TafsilID INNER JOIN" +
					" Tafsil AS Tafsil_1 ON ProductBoughtSupplier.CommissionAcc = Tafsil_1.TafsilID INNER JOIN" +
					" Tafsil AS Tafsil_2 ON ProductBoughtSupplier.CommissionTo = Tafsil_2.TafsilID" +
					" WHERE     (ProductBoughtSupplier.ReceiptNo = ?)");
			
			stmt.setInt(1,receiptID);
			rs=stmt.executeQuery();
			
			while(rs.next())
			{
				addRow(rs.getInt(1),rs.getString(2),
						null,rs.getFloat(3),rs.getFloat(5),
						purchaseTableModel);
			}
			
		} catch (SQLException SQLEx) {
			GUITools.displayErrorInformation(PurchaseDetailFrame.this,SQLEx);
			SQLEx.printStackTrace();
		}finally
		{
			rs=DBTools.clearRes(rs);
			stmt=DBTools.clearRes(stmt);
		}
	}