In this article I will explain with an example, how to populate Google Maps V3 with Multiple Markers using SQL Server database in ASP.Net Website.
 
Database
For this article I have created a Custom database called as LocationDB in which I have created the following table named as Locations.
ASP.Net : Google Maps V3 with Multiple Markers Database Example
 
In the above table I have inserted Longitude and Latitude information of three different cities, along with their names and descriptions.
ASP.Net : Google Maps V3 with Multiple Markers Database Example
 
 
HTML Markup and Google Maps Scripts
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
var markers = [
<asp:Repeater ID="rptMarkers" runat="server">
<ItemTemplate>
            {
            "title": '<%# Eval("Name") %>',
            "lat": '<%# Eval("Latitude") %>',
            "lng": '<%# Eval("Longitude") %>',
            "description": '<%# Eval("Description") %>'
        }
</ItemTemplate>
<SeparatorTemplate>
    ,
</SeparatorTemplate>
</asp:Repeater>
];
</script>
<script type="text/javascript">
    window.onload = function () {
        var mapOptions = {
            center: new google.maps.LatLng(markers[0].lat, markers[0].lng),
            zoom: 8,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        var infoWindow = new google.maps.InfoWindow();
        var map = new google.maps.Map(document.getElementById("dvMap"), mapOptions);
        for (i = 0; i < markers.length; i++) {
            var data = markers[i]
            var myLatlng = new google.maps.LatLng(data.lat, data.lng);
            var marker = new google.maps.Marker({
                position: myLatlng,
                map: map,
                title: data.title
            });
            (function (marker, data) {
                google.maps.event.addListener(marker, "click", function (e) {
                    infoWindow.setContent(data.description);
                    infoWindow.open(map, marker);
                });
            })(marker, data);
        }
    }
</script>
<div id="dvMap" style="width: 500px; height: 500px">
</div>
 
In the above HTML Markup I have made use of the Google Maps Script to load Google Maps V3 with Multiple Markers. Now in order to populate it from the database I have made use of an ASP.Net Repeater Control to populate the markers array. Thus when the page is rendered in the browser the values from database are loaded within the marker array.
 
 

Namespaces
You will need to import the following namespaces.
C#
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
 
VB.Net
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
 
 
Populating the Google Maps Marker from SQL Server Database
In the Page_Load event of the ASP.Net Page I am populating the ASP.Net Repeater control using the records from the Locations table of the SQL Server database.
C#
protected void Page_Load(object sender, EventArgs e)
{
   if (!this.IsPostBack)
    {
        DataTable dt = this.GetData("select * from Locations");
        rptMarkers.DataSource = dt;
        rptMarkers.DataBind();
    }
}
 
private DataTable GetData(string query)
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    SqlCommand cmd = new SqlCommand(query);
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter())
        {
            cmd.Connection = con;
 
            sda.SelectCommand = cmd;
            using (DataTable dt = new DataTable())
            {
                sda.Fill(dt);
                return dt;
            }
        }
    }
}
 
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = Me.GetData("select * from Locations")
        rptMarkers.DataSource = dt
        rptMarkers.DataBind()
    End If
End Sub
 
Private Function GetData(query As String) As DataTable
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Dim cmd As New SqlCommand(query)
    Using con As New SqlConnection(conString)
        Using sda As New SqlDataAdapter()
            cmd.Connection = con
 
            sda.SelectCommand = cmd
            Using dt As New DataTable()
                sda.Fill(dt)
                Return dt
            End Using
        End Using
    End Using
End Function
 
 
Screenshot
ASP.Net : Google Maps V3 with Multiple Markers Database Example
 
 
Demo
 
 
Downloads