Most likely your values $latitude
and/or $longitude
are not what you expect them to be. So radians($latitdue)
becomes radians()
or radians('')
.
For getting a single row, get_row()
is usually the better choice instead of get_results()
.
$zipdetail = $wpdb->get_row( "SELECT * FROM `li_zipcode` WHERE `zip_code` = '$zipcode'", OBJECT );
If $zipcode
is coming from an untrusted source (e.g. user input), make sure to use a prepared statement:
$zipdetail = $wpdb->get_row(
$wpdb->prepare(
'SELECT latitude, longitude FROM `li_zipcode` WHERE `zip_code` = %d',
$zipcode
),
OBJECT
);