$sql = "INSERT INTO postcode
(postcode,
lat,
lon,
osEasting,
osNorthing,
osRef6)
VALUES ('" . str_replace(" ", "", $data[0]) . "',
'" . round($lat,6) . "',
'" . round($lon,6) . "',
'" . round($data[2]) . "',
'" . round($data[3]) . "',
'" . $osref . "'
)
ON DUPLICATE KEY UPDATE
postcode = '" . str_replace(" ", "", $data[0]) . "',
lat = '" . round($lat,6) . "',
lon = '" . round($lon,6) . "',
osEasting = '" . round($data[2]) . "',
osNorthing = '" . round($data[3]) . "',
osRef6 = '" . $osref . "'";