Question

我可以从我的MySQL表中提取这些信息并显示我需要的信息，但是我想要了解如何使用我当前的代码每隔5秒左右刷新一次这些数据。

没有太多数据需要显示，就像任何给定时间的5或8个标记一样。我已经包含了我用来提取数据的当前代码。我对PHP / MySQL很好，但对谷歌地图来说却很新。我尝试添加代码以刷新谷歌地图

 setInterval(function() {
$.ajax({ url: '/localhost/my/site.php',
 data: {action: 'test'},
 type: 'post',
  success: function(output) {
      alert('hi');
     // change the DOM with your new output info
  }
});
}, 5000);

但我的代码仍然无法解决问题？当mysql数据库更新时，是否可以从mysql获取新数据？

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?  sensor=true" /></script>

<script type='text/javascript'>
//This javascript will load when the page loads.
jQuery(document).ready( function($){
setInterval(function() {
  $.ajax({ url: '/localhost/my/site.php',
 data: {action: 'test'},
 type: 'post',
  success: function(output) {
      alert('hi');
     // change the DOM with your new output info
  }
 });
   }, 5000); 

    //Initialize the Google Maps
    var geocoder;
    var map;
    var markersArray = [];
    var infos = [];

    geocoder = new google.maps.Geocoder();
    var myOptions = {
          zoom: 8,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        }
    //Load the Map into the map_canvas div
    var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
    map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

    //Initialize a variable that the auto-size the map to whatever you are plotting
    var bounds = new google.maps.LatLngBounds();

    //Initialize the encoded string       
    var encodedString;

    //Initialize the array that will hold the contents of the split string
    var stringArray = [];

    //Get the value of the encoded string from the hidden input
    encodedString = document.getElementById("encodedString").value;

    //Split the encoded string into an array the separates each location
    stringArray = encodedString.split("****");

    var x;
 for (x = 0; x < stringArray.length; x = x + 1)
    {
        var addressDetails = [];
        var marker;
        //Separate each field
        addressDetails = stringArray[x].split("&&&");
        //Load the lat, long data
        var lat = new google.maps.LatLng(addressDetails[1], addressDetails[2]);
        var image = new google.maps.MarkerImage(addressDetails[3]);

        //Create a new marker and info window
        var marker = new google.maps.Marker({
            map: map,
            icon: image,
            position: lat,
            content: addressDetails[0]
        });



        //Pushing the markers into an array so that it's easier to manage them
        markersArray.push(marker);
        google.maps.event.addListener( marker, 'click', function () {
            closeInfos();
            var info = new google.maps.InfoWindow({content: this.content});
            //On click the map will load the info window
            info.open(map,this);
            infos[0]=info;
        });




       //Extends the boundaries of the map to include this new location
       bounds.extend(lat);
    }
    //Takes all the lat, longs in the bounds variable and autosizes the map
    map.fitBounds(bounds);



    //Manages the info windows
    function closeInfos(){
   if(infos.length > 0){
      infos[0].set("marker",null);
      infos[0].close();
      infos.length = 0;
   }
    }

});
</script>

</head>
<body>
<div id='input'>

<?php


//Initialize your first couple variables
$encodedString = ""; //This is the string that will hold all your location data
$x = 0; //This is a trigger to keep the string tidy

//Now we do a simple query to the database

// DB  INFO CONNECTION IS HERE AND WORKS

$result = mysql_query("SELECT * FROM `ulocation` WHERE `ul_lat`!='' AND `ul_long`!=''  
AND `ul_onduty`='1'",$db1);

//Multiple rows are returned
while ($row = mysql_fetch_array($result, MYSQL_NUM))
{
    //This is to keep an empty first or last line from forming, when the string is 
split
    if ( $x == 0 )
    {
         $separator = "";
    }
    else
    {
         //Each row in the database is separated in the string by four *'s
         $separator = "****";
    }
    $status='0';
    $cadd  = sql::getval('cal_address', 'call', "WHERE    `cal_id`='$row[14]'");
    $num  = sql::getval('cal_num', 'call', "WHERE `cal_id`='$row[14]'");
    $pcond  = sql::getval('cal_pcond', 'call', "WHERE `cal_id`='$row[14]'");
    $list="$num $cadd";
    //Saving to the String, each variable is separated by three &'s
$encodedString = $encodedString.$separator."<table border=0 width='350' height='20'    
class='maincolm' cellpadding=0   cellspacing=0><td align=left valign=top><h2></h2></td>  
<tr><td width=100%><font size=3  face=arial><p><b>".$row[2].
        "</b>".
        "<br>Address: $list".
        "<br>Call Type: $pcond".
        "<br><br>Lat: ".$row[5].
        "<br>Long: ".$row[6].
        "</td></table>".
        "</p>&&&".$row[5]."&&&".$row[6]."&&&".$row[8]."&&&".$row[14];
       $x = $x + 1;
    }        
   ?>
<input type="hidden" id="encodedString" name="encodedString" value="<?php echo   
$encodedString; ?>" />
 <? echo "<body oncontextmenu=\"return false\" style=\"overflow: hidden; \"   
topmargin=0 leftmargin=0 rightmargin=0 bottommargin=0>";
  <div id=\"map_canvas\"></div>
  </body>
  </html>";
 ?>

任何帮助将不胜感激

Answer 1

根据此处的链接

Live update notification on database changes MYSQL PHP

How can I view live MySQL queries?

我的结论建议使用轮询，每隔X秒进行数据库调用以更新标记信息。

另外，在mysql中提到使用触发器的帖子中有1个，你也可以看一下。

鉴于mysql没有通知

作为对您目的的建议。如果您想要从标记刷新数据，例如标记onclick事件，那么您可以进行数据库调用以刷新标记。多数民众赞成我如何为标记onclick立即

做这件事

希望有所帮助

是否可以立即刷新Google地图？

1 个答案: