private static void InsertItemWithDbGeographyValue()
{
using (ReservationContext ctx = new ReservationContext()) {
AccommodationProperty accommProperty = new AccommodationProperty {
Name = "Club & Hotel Letoonia",
// In order: POINT(Long Lat)
Location = DbGeography.FromText("POINT(29.097218832015983 36.63622153677499)")
};
ctx.AccommodationProperties.Add(accommProperty);
ctx.SaveChanges();
}
}
private static void GetNearestAccommodationPropertiesWithSpecificDistance(DbGeography targetLocation, float distanceInKm)
{
using (ReservationContext ctx = new ReservationContext()) {
float distanceInMeters = (distanceInKm * 1000);
var accommProperties = (from accommProperty in ctx.AccommodationProperties
let distance = accommProperty.Location.Distance(targetLocation)
where distance <= distanceInMeters
orderby distance
select new {
Name = accommProperty.Name,
Distance = distance
}).ToArray();
foreach (var accommProperty in accommProperties)
{
Console.WriteLine("Name: {0}, Distance: {1} meters", accommProperty.Name, accommProperty.Distance);
}
}
}
private static void GetNearestAccommodationProperties(DbGeography targetLocation, int takeTop)
{
// ref: http://www.west-wind.com/weblog/posts/2012/Jun/21/Basic-Spatial-Data-with-SQL-Server-and-Entity-Framework-50
// quote: The STDistance function returns the straight line distance between the passed
// in point and the point in the database field. The result for
// SRID 4326 is always in meters.
using (ReservationContext ctx = new ReservationContext()) {
// Order by distance (nearest one is at the top)
var accommProperties = (from accommProperty in ctx.AccommodationProperties
let distance = accommProperty.Location.Distance(targetLocation)
orderby distance
select new {
Name = accommProperty.Name,
Distance = distance
}).Take(takeTop).ToArray();
foreach (var accommProperty in accommProperties)
{
Console.WriteLine("Name: {0}, Distance: {1} meters", accommProperty.Name, accommProperty.Distance);
}
}
}
