SqlGeography.STBuffer Method (Double)


Returns a geography object that represents the union of all points whose distance from a SqlGeography instance is less than or equal to a specified value.

Namespace:   Microsoft.SqlServer.Types
Assembly:  Microsoft.SqlServer.Types (in Microsoft.SqlServer.Types.dll)

[SqlMethodAttribute(IsDeterministic = true, IsPrecise = false)]
public SqlGeography STBuffer(
	double distance


Type: System.Double

Is a double that specifies the distance from the geography instance around which to calculate the buffer.

Return Value

Type: Microsoft.SqlServer.Types.SqlGeography

A double that represents the union of all points that are the specified distance from the current SqlGeography.

The STBuffer method calculates a buffer in the same manner as BufferWithTolerance, specifying tolerance = distance * .001 and relative = false.

A negative buffer removes all points within the given distance of the boundary of the SqlGeography instance.

The following example creates a LineString geography instance. It then uses the STBuffer method to return the region within 1 meter of the instance.

DECLARE @g SqlGeography;
SET @g = SqlGeography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326);
SELECT @g.STBuffer(1).ToString();
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