My array looks very similar to this. I need to create a single row for the items that have the same order number for CSV export. I'd prefer to do this PHP wise instead of SQL. But would appreciate any help I can get. $ar = array( array( "order_id" => "34", "order_number" => "35Y345Y356YU3", "order_name" => "Steinway Grand Piano #11", "order_ordered_size" => "Grand", "order_sales_price" => "78671.90", "order_shipping_price" => "7.85", "order_shipping_extra" => "0.06", ), array( "order_id" => "35", "order_number" => "35Y345Y356YU3", "order_name" => "Bechstein", "order_ordered_size" => "Grand", "order_sales_price" => "11671.90", "order_shipping_price" => "51.00", "order_shipping_extra" => "450.00", ), array( "order_id" => "36", "order_number" => "35Y345Y356YU3", "order_name" => "Bosendorfer", "order_ordered_size" => "Grand", "order_sales_price" => "11671.90", "order_shipping_price" => "500.00", "order_shipping_extra" => "450.00", ), array( "order_id" => "37", "order_number" => "78973467Y3Y36", "order_name" => "Steinway Grand Piano #11", "order_ordered_size" => "Grand", "order_sales_price" => "78671.90", "order_shipping_price" => "7.85", "order_shipping_extra" => "0.06", ), array( "order_id" => "38", "order_number" => "78973467Y3Y36", "order_name" => "Baldwin L Grand Piano #39", "order_ordered_size" => "Grand", "order_sales_price" => "11671.90", "order_shipping_price" => "1.00", "order_shipping_extra" => "450.00", ) );