Question

我有一个代码，应该从数据库中获取数据（纬度和经度）并将其与标记一起显示在谷歌地图上，问题是它只获取并显示只有一行的纬度和经度，但它应该是显示所有的地方。如果有人能帮助我，我将不胜感激。

<script>
    <?php 
    require 'connection.php'; 
    $parent_id = $_GET['country'];
    $fid = $_GET['fid']; 
        $sql = "SELECT * FROM features_for_office WHERE parent_id='".$parent_id."' and fid='".$fid."' ";
        $result = mysqli_query($con, $sql);
        if (mysqli_num_rows($result) > 0) 
            {
              while($row = mysqli_fetch_assoc($result)) 
               {
                 $officeid= $row["officeid"];

                 $sql1 = "SELECT * FROM register_office WHERE id='".$officeid."' ";
                 $result1 = mysqli_query($con, $sql1);
                  if (mysqli_num_rows($result1) > 0) 
                  {
                   while($row1 = mysqli_fetch_assoc($result1)) 
                   {
                    $officelat= $row1["lat"];
                    $officelon= $row1["lon"];
                    $officetitle= $row1["officetitle"];

                     //echo $officelat; 
                     //echo $officelon;
                     //echo $officetitle;
                  ?>    
                   var myCenter=new google.maps.LatLng(<?php echo $officelat;?>,<?php echo $officelon;?>);
                   function initialize()
                   {
                    var mapProp = {
                    center:myCenter,
                    zoom:5,
                    mapTypeId:google.maps.MapTypeId.ROADMAP
                    };
                    var map=new google.maps.Map(document.getElementById("googleMap"),mapProp);
                    var marker=new google.maps.Marker({
                    position:myCenter,
                    });
                    marker.setMap(map);
                    var infowindow = new google.maps.InfoWindow({
                    content:"<?php echo $officetitle;?>"
                    });

                   infowindow.open(map,marker);}
                   google.maps.event.addDomListener(window, 'load', initialize);
                 <?}
                 }
              }
          } 
    mysqli_close($con);     
 ?>
   </script>
   <div id="googleMap" style="width:1145px;height:380px;"></div>

Answer 1

错误是你每次都要初始化地图，直到循环完成，它会每次重新创建地图，最后的latlon标记将显示在地图上。在页面加载时调用initialize方法并放置以下代码在循环中。

var myCenter=new google.maps.LatLng(<?php echo $officelat;?>,<?php echo $officelon;?>);
                  var marker=new google.maps.Marker({
                    position:myCenter,
                    });
                    marker.setMap(map);

Answer 2

使用SQL，您可以使用以下代码从数据库中获取纬度和经度：

protected void googleMap_Load(object sender, EventArgs e) 
    {
        //Establishing SQL connection
        SqlConnection connStr = new
        SqlConnection(ConfigurationManager.ConnectionStrings["myConnectionString"].ConnectionString);
        connStr.Open();//Open the connection to Database

        //Generate the database query to fetch the content details
        SqlCommand cmd = new SqlCommand("select LAT,LON from DATA where ID=9", connStr);

        SqlDataAdapter sqlda = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();

        sqlda.Fill(ds);

    }

问题仍然存在，如何使用此dataTable在谷歌地图上设置标记... 可以重新设置问题以从数据库中获取LatLng 我用脚本来显示地图

<script>
    var myLatLon = new google.maps.LatLng(13, 77);//Defining Latitude and Longitude 

    var mapProp = {
        center: myLatLon, //    Center of display page.
        zoom: 8, //Zoom level
        mapTypeId: google.maps.MapTypeId.ROADMAP
    }
    var map = new google.maps.Map(document.getElementById('dvMap'), mapProp);

    var marker = new google.maps.Marker({
        position: myLatLon,
        map: map,
    });
</script>

从数据库中获取多个纬度和经度，并在谷歌地图上显示其标记

2 个答案: