An Error Was Encountered

Error Number: 1054

Unknown column 'content' in 'where clause'

SELECT CONCAT( 3d_chip_details.semicon, ' ', 3d_ref_boards.product_name, ' ', 3d_ref_boards.memory_quantity, 'MiB' ) b, 3d_ref_boards.board_id, 3d_chip_details.chip_name chip_name FROM 3d_ref_boards, 3d_chip_details WHERE 3d_ref_boards.chip_id = 3d_chip_details.chip_id AND 3d_chip_details.chip_id = content AND 3d_chip_details.live_date < 'NOW()' AND ifnull(3d_ref_boards.live_date, CURRENT_TIMESTAMP()) <= CURRENT_TIMESTAMP()