MySQL server has gone away
fetch_all(

array (
  0 => '
			SELECT
				wh_invoice_detail.*,
				wh_invoice.type,
				wh_invoice.warehouse_id,
				wh_category.name as warehouse_name
			FROM
				wh_invoice_detail
				left outer join wh_invoice on wh_invoice.id = wh_invoice_detail.`invoice_id`
				left outer join wh_category on wh_category.id =  wh_invoice.warehouse_id
			WHERE
				wh_invoice_detail.wh_item_code = "BT50029" 
		',
)

array (
  0 => 'BT50029',
)