In programming you need to parse the data while doing the process of json serialization or converting the data into of JSON type means in key value pair form.

So for doing that you need to use the predefined function that will recreate the contents for the coder before the conversion process.

SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(dt);
                System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
                List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
                Dictionary<string, object> row;
                foreach (DataRow dr in dt.Rows)
                {
                    row = new Dictionary<string, object>();
                    foreach (DataColumn col in dt.Columns)
                    {
                        row.Add(col.ColumnName, dr[col]);
                    }
                    rows.Add(row);
                }
                return serializer.Serialize(rows);

Above code is to serialize the database rows

 function initialize() {
        var markers = JSON.parse('<%=ConvertDataTabletoString() %>');
        var mapOptions = {
        center: new google.maps.LatLng(markers[0].lat, markers[0].lng),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
//  marker:true
};

Above code is to deserialize the database records into your function.