Loading city/state from SQL Server to Google Maps?

I'm trying to make a small application that takes a city & state and geocodes that address to a lat/long location. Right now I am utilizing Google Map's API, ColdFusion, and SQL Server. Basically the city and state fields are in a database table and I want to take those locations and get marker put on a Google Map showing where they are.

This is my code to do the geocoding, and viewing the source of the page shows that it is correctly looping through my query and placing a location ("Omaha, NE") in the address field, but no marker, or map for that matter, is showing up on the page:

function codeAddress() {
<cfloop query="GetLocations">
    var address = document.getElementById(<cfoutput>#Trim(hometown)#,#Trim(state)#</cfoutput>).value;
      if (geocoder) {
         geocoder.geocode( {<cfoutput>#Trim(hometown)#,#Trim(state)#</cfoutput>: address}, function(results, status) {
         if (status == google.maps.GeocoderStatus.OK) {
             var marker = new google.maps.Marker({
             map: map, 
             position: results[0].geometry.location,
             title: <cfoutput>#Trim(hometown)#,#Trim(state)#</cfoutput>
             });
         } else {
            alert("Geocode was not successful for the following reason: " + status);
            }
         });
      }     
</cfloop> }

And here is the code to initialize the map:

var geocoder;
var map;

function initialize() {
    geocoder = new google.maps.Geocoder();
    var latlng = new google.maps.LatLng(42.4167,-90.4290);
    var myOptions = {
      zoom: 5,
      center: latlng,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    }
    var marker = new google.maps.Marker({
          position: latlng,
          map: map,
          title: "Test"
      });
    map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
}

I do have a map working that uses lat/long that was hard coded into the database table, but I want to be able to just use the city/state and convert that to a lat/long. Any suggestions or direction? Storing the lat/long in the database is also possible, but I don't know how to do that within SQL.

Daniel Vassallo

You may want to consider the following example:

Using the V2 API:

<!DOCTYPE html>
<html> 
<head> 
  <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> 
  <title>Google Maps API Geocoding Demo</title> 
  <script src="http://maps.google.com/maps?file=api&amp;v=2&amp;sensor=false"
          type="text/javascript"></script> 
</head> 
<body onunload="GUnload()"> 

  <div id="map_canvas" style="width: 400px; height: 300px"></div> 

  <script type="text/javascript"> 

    // Prepare this list from ColdFusion
    var locations = [
       'New York, NY',
       'Los Angeles, CA',
       'Chicago, IL',
       'Houston, TX',
       'Phoenix, AZ'
    ];

    if (GBrowserIsCompatible()) {
       var map = new GMap2(document.getElementById("map_canvas"));

       var geocoder = new GClientGeocoder();
       var index = 0;

       var geocoderFunction = function () { 
          geocoder.getLatLng(locations[index], function (point) {    
             if (point) {
                map.addOverlay(new GMarker(point));                
             }

             // Call the geocoder with a 100ms delay
             index++;
             if (locations.length > index) {
                setTimeout(geocoderFunction, 100);
             }
          });
       }

       map.setCenter(new GLatLng(38.00, -100.00), 3);

       // Launch the geocoding process
       geocoderFunction();
    }
  </script> 
</body>
</html>

Using the V3 API:

<!DOCTYPE html>
<html> 
<head> 
  <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> 
  <title>Google Maps API Geocoding Demo</title> 
  <script src="http://maps.google.com/maps/api/js?sensor=false" 
          type="text/javascript"></script>
</head> 
<body> 

  <div id="map_canvas" style="width: 400px; height: 300px"></div> 

  <script type="text/javascript"> 

    // Prepare this list from ColdFusion
    var locations = [
       'New York, NY',
       'Los Angeles, CA',
       'Chicago, IL',
       'Houston, TX',
       'Phoenix, AZ'
    ];

    var mapOpt = { 
       mapTypeId: google.maps.MapTypeId.TERRAIN,
       center: new google.maps.LatLng(38.00, -100.00),
       zoom: 3
    };

    var map = new google.maps.Map(document.getElementById("map_canvas"), mapOpt);

    var geocoder = new google.maps.Geocoder();
    var index = 0;

    var geocoderFunction = function () { 
       geocoder.geocode({ 'address': locations[index] }, function (results, status) {
          if (status == google.maps.GeocoderStatus.OK) {
             new google.maps.Marker({
                map: map, 
                position: results[0].geometry.location
             });             
          }

          // Call the geocoder with a 100ms delay
          index++;
          if (locations.length > index) {
             setTimeout(geocoderFunction, 100);
          }
       });
    }

    // Launch the geocoding process
    geocoderFunction();
  </script> 
</body>
</html>

All you need to do is to render the JavaScript array locations from ColdFusion, instead of using the hardcoded one in the example.

Screenshot from the above example:

You need to actually add the marker to the map using the addOverlay method:

var point = new GLatLng(...);
map.addOverlay(new GMarker(point));

You can also add instances of the Marker class to your map:

map.addOverlay(marker);

See the Map Overlays docs:

http://code.google.com/apis/maps/documentation/javascript/v2/overlays.html

来源：https://stackoverflow.com/questions/2899506/loading-city-state-from-sql-server-to-google-maps

标签

javascript

sql-server

google-maps

coldfusion

geocoding