Auto fill country and city from zip code, and the oposite

Question

I am trying to make a simple form that requires address and zip code, so I was wondering if there is a way to auto populate those fields based on what the user has already typed.

So for example if he decides to enter only the zip code the city and country fields will be filled automatically and vice-versa.

After searching a while I found these databases that I could possibly use

• Link 1
• Link 2

But apart from that I am not sure how to do this using PHP and MySQL. any help would be appreciated.

Answer 1

*This is very easy what u need to do is just get the zip code from the user and with that you can get the $country and $city using google api.here i give you an example of how i am getting longitude and latitude from the postalcode i.e. zip code.

$postcode=$_POST('postcode');
                if($postcode)
                {

                    $address = urlencode($postcode);
                    $url='http://maps.googleapis.com/maps/api/geocode/json?address='.$address.'&sensor=false';

                    $ch = curl_init(); 
                    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
                    curl_setopt($ch, CURLOPT_URL, $url);
                    $data = curl_exec($ch);
                    curl_close($ch);
                    $source = $data;
                    $obj = json_decode($source);
                    $lat = $obj->results[0]->geometry->location->lat;
                    $long = $obj->results[0]->geometry->location->lng;


                }
$longitude=$long;
$latitude=$lat;

than you can insert the above two variables $longitude and $latitude in your database.simple as that :) .go to the following link https://developers.google.com/maps/documentation/geocoding/?csw=1

now for getting the country name from longitude and latitude use reverse geocoding. supply a comma-separated latitude/longitude pair in the latLng parameter.

 var geocoder;
  var map;
  var infowindow = new google.maps.InfoWindow();
  var marker;
  function initialize() {
    geocoder = new google.maps.Geocoder();
    var latlng = new google.maps.LatLng(40.730885,-73.997383);
    var mapOptions = {
      zoom: 8,
      center: latlng,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    }
    map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
  }

  function codeLatLng() {
    var input = document.getElementById("latlng").value;
    var latlngStr = input.split(",",2);
    var lat = parseFloat(latlngStr[0]);
    var lng = parseFloat(latlngStr[1]);
    var latlng = new google.maps.LatLng(lat, lng);//here you will get your country and city name
    geocoder.geocode({'latLng': latlng}, function(results, status) {
      if (status == google.maps.GeocoderStatus.OK) {
        if (results[1]) {
          map.setZoom(11);
          marker = new google.maps.Marker({
              position: latlng,
              map: map
          });
          infowindow.setContent(results[1].formatted_address);
          infowindow.open(map, marker);
        }
      } else {
        alert("Geocoder failed due to: " + status);
      }
    });
  }

read about reverse geocodng here and modify the code according to your needs https://developers.google.com/maps/documentation/javascript/geocoding#ReverseGeocoding

Use : getLocations(latlng:GLatLng, callback:function)

This method performs reverse-geocoding, the conversion of a latitude/longitude pair into human-readable addresses. getLocations() sends a request to the Google geocoding service, asking it to return the address for the given latlng and pass the response in the given callback.

As this method requires a call to a Google server, you must also pass a callback method to handle the response. This response will contain a Status code, and if successful, one or more Placemark objects.

Note that this method may instead pass an addressable String, as indicated above; in that case, the service will do a standard geocode. If however, the first argument contains a GLatLng, the service will do a reverse-geocode.

Answer 2

You can do what @RoyalBg sais but if "based on what the user has already typed" you should add a column userid

SELECT zip_code FROM locations WHERE country like '%$country%' and userid = 254