# Class NpgsqlNetTopologySuiteDbFunctionsExtensions

Namespace
  Microsoft.EntityFrameworkCore

Assembly
  Npgsql.EntityFrameworkCore.PostgreSQL.NetTopologySuite.dll

Provides Npgsql-specific spatial extension methods on DbFunctions.

    public static class NpgsqlNetTopologySuiteDbFunctionsExtensions

Inheritance
  object
  NpgsqlNetTopologySuiteDbFunctionsExtensions

Inherited Members
  object.Equals(object)
  object.Equals(object, object)
  object.GetHashCode()
  object.GetType()
  object.MemberwiseClone()
  object.ReferenceEquals(object, object)
  object.ToString()

## Methods

### Distance(DbFunctions, Geometry, Geometry, bool)

Returns the minimum distance between the origin geometry and another geometry g. Translates to `ST_Distance`.

    public static double Distance(this DbFunctions _, Geometry geometry, Geometry anotherGeometry, bool useSpheroid)

#### Parameters

`_` DbFunctions

  The DbFunctions instance.

`geometry` Geometry

  The origin geometry.

`anotherGeometry` Geometry

  The geometry from which to compute the distance.

`useSpheroid` bool

  Whether to use sphere or spheroid distance measurement.

#### Returns

double

  The distance between the geometries.

#### Remarks

See https://postgis.net/docs/ST_Distance.html.

### DistanceKnn(DbFunctions, Geometry, Geometry)

Returns the 2D distance between two geometries. Used in the "ORDER BY" clause, provides index-assisted nearest-neighbor result sets. Translates to `<->`.

    public static double DistanceKnn(this DbFunctions _, Geometry geometry, Geometry anotherGeometry)

#### Parameters

`_` DbFunctions

  The DbFunctions instance.

`geometry` Geometry

  The origin geometry.

`anotherGeometry` Geometry

  The geometry from which to compute the distance.

#### Returns

double

  The 2D distance between the geometries.

#### Remarks

See https://postgis.net/docs/ST_Distance.html.

### Force2D<TGeometry>(DbFunctions, TGeometry)

Forces the geometries into a "2-dimensional mode" so that all output representations will only have the X and Y coordinates. Translates to `ST_Force2D(geometry)`

    public static TGeometry Force2D<TGeometry>(this DbFunctions _, TGeometry geometry) where TGeometry : Geometry

#### Parameters

`_` DbFunctions
`geometry` TGeometry

#### Returns

TGeometry

#### Type Parameters

`TGeometry`

#### Remarks

See https://postgis.net/docs/ST_Force2D.html.

### IsWithinDistance(DbFunctions, Geometry, Geometry, double, bool)

Tests whether the distance from the origin geometry to another is less than or equal to a specified value. Translates to `ST_DWithin`.

    public static bool IsWithinDistance(this DbFunctions _, Geometry geometry, Geometry anotherGeometry, double distance, bool useSpheroid)

#### Parameters

`_` DbFunctions

  The DbFunctions instance.

`geometry` Geometry

  The origin geometry.

`anotherGeometry` Geometry

  The geometry to check the distance to.

`distance` double

  The distance value to compare.

`useSpheroid` bool

  Whether to use sphere or spheroid distance measurement.

#### Returns

bool

  true if the geometries are less than distance apart.

#### Remarks

See https://postgis.net/docs/ST_DWithin.html.

### Transform<TGeometry>(DbFunctions, TGeometry, int)

Returns a new geometry with its coordinates transformed to a different spatial reference system. Translates to `ST_Transform(geometry, srid)`.

    public static TGeometry Transform<TGeometry>(this DbFunctions _, TGeometry geometry, int srid) where TGeometry : Geometry

#### Parameters

`_` DbFunctions
`geometry` TGeometry
`srid` int

#### Returns

TGeometry

#### Type Parameters

`TGeometry`

#### Remarks

See https://postgis.net/docs/ST_Transform.html.