DbGeography Intersects Method Doesn't Work

Question

The System.Data.Spatial.DbGeography.Intersects method always returns true for me. I do not know why this is happening. I created a simple command line snippet below, which leads to the console output below

Intersects
Intersects

The point is clearly not anywhere near the borders and therefore should not intersect.

DbGeography bounds = DbGeography.PolygonFromText("POLYGON ((146 -20,148 -20,148 -22,146 -22,146 -20))", 4326);
DbGeography point = DbGeography.PointFromText("POINT (0 0)", 4326);
if (point.Intersects(bounds) == true)
    Console.WriteLine("Intersects");
else
    Console.WriteLine("Does NOT intersect");

if (bounds.Intersects(point) == true)
    Console.WriteLine("Intersects");
else
    Console.WriteLine("Does NOT intersect");

Answer 1

The point is clearly not anywhere near the borders and therefore should not intersect.

There is a rule: as soon as you pronounce "clearly", prepare for the wrong. :)

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POLYGON ((146 -20,146 -22,148 -22,148 -20,146 -20))

, , ? , , , (90 = ), . EnvelopeAngle ( DbGeography #), . ( , , , #) , ReorientObject.

Answer 2

, , , - . SQL Server , , , , - ( ). " " , ( ), , SQL Server . .

, :

public bool IsInside(DbGeography polygon, double longitude, double latitude)
{
    DbGeography point = DbGeography.FromText(string.Format("POINT({1} {0})", latitude.ToString().Replace(',', '.'), longitude.ToString().Replace(',', '.')), DbGeography.DefaultCoordinateSystemId);

    var wellKnownText = polygon.AsText();

    var sqlGeography =
        SqlGeography.STGeomFromText(new SqlChars(wellKnownText), DbGeography.DefaultCoordinateSystemId)
            .MakeValid();

    //Now get the inversion of the above area
    var invertedSqlGeography = sqlGeography.ReorientObject();

    //Whichever of these is smaller is the enclosed polygon, so we use that one.
    if (sqlGeography.STArea() > invertedSqlGeography.STArea())
    {
        sqlGeography = invertedSqlGeography;
    }

    polygon = DbSpatialServices.Default.GeographyFromProviderValue(sqlGeography);

    return point.Intersects(polygon);
}

, Entity Framework 5 <:

Polygon Multipolygon .

public static DbGeography MakePolygonValid(this DbGeography geom)
{
    var wellKnownText = geom.AsText();

    //First, get the area defined by the well-known text using left-hand rule
    var sqlGeography =
        SqlGeography.STGeomFromText(new SqlChars(wellKnownText), DbGeography.DefaultCoordinateSystemId)
            .MakeValid();

    //Now get the inversion of the above area
    var invertedSqlGeography = sqlGeography.ReorientObject();

    //Whichever of these is smaller is the enclosed polygon, so we use that one.
    if (sqlGeography.STArea() > invertedSqlGeography.STArea())
    {
        sqlGeography = invertedSqlGeography;
    }
    return DbSpatialServices.Default.GeographyFromProviderValue(sqlGeography);
}

, Intersects .

public static class GeoHelper
{
    public const int SridGoogleMaps = 4326;
    public const int SridCustomMap = 3857;

    public static DbGeography PointFromLatLng(double lat, double lng)
    {
        return DbGeography.PointFromText(
            "POINT("
            + lng.ToString(CultureInfo.InvariantCulture) + " "
            + lat.ToString(CultureInfo.InvariantCulture) + ")",
            SridGoogleMaps);
    }
}

public County GetCurrentCounty(double latitude, double longitude)
{
    var point = GeoHelper.PointFromLatLng(latitude, longitude);

    var county = db.Counties.FirstOrDefault(x =>
        x.Area.Intersects(point));

    return county;
}

T-SQL, Entity Framework:

SELECT TOP (1) 
[Extent1].[Id] AS [Id], 
[Extent1].[Name] AS [Name], 
[Extent1].[Code] AS [Code], 
[Extent1].[Area] AS [Area]
FROM [Election].[County] AS [Extent1]
WHERE ([Extent1].[Area].STIntersects(@p__linq__0)) = 1


-- p__linq__0: 'POINT (10.0000000 32.0000000)' (Type = Object)

:

declare @p__linq__0 varchar(max)
set @p__linq__0 = 'POINT (10.0000000 32.0000000)' 

SELECT TOP (1) 
    [Extent1].[Id] AS [Id], 
    [Extent1].[Name] AS [Name], 
    [Extent1].[Code] AS [Code], 
    [Extent1].[Area] AS [Area]
    FROM [Election].[County] AS [Extent1]
    WHERE ([Extent1].[Area].STIntersects(@p__linq__0)) = 1

:

https://docs.microsoft.com/en-us/sql/t-sql/spatial-geometry/stintersects-geometry-data-type

:

, dbgeometry/dbgeography dbgeometry