ST_CurvePolyToPoly method

Returns the interpolation of the curve polygon as a polygon.

Syntax

curvepolygon-expression.ST_CurvePolyToPoly()

Returns

ST_Polygon Returns the interpolation of the curvepolygon-expression as a polygon.
The spatial reference system identifier of the result is the same as the spatial reference system of the curvepolygon-expression.

If curvepolygon-expression is empty, the ST_CurvePolyToPoly method returns an empty set of type ST_Polygon. Otherwise, ST_CurvePolyToPoly returns a polygon containing any linear rings in curvepolygon-expression combined with the interpolation of any circularstring or compound curve rings in curvepolygon-expression.

Note

By default, ST_CurvePolyToPoly uses the original format for a geometry, if it is available. Otherwise, the internal format is used. For more information about internal and original formats, see STORAGE FORMAT clause, CREATE SPATIAL REFERENCE SYSTEM statement.

Standards and compatibility

Example

The following example returns the result Polygon ((0 0, 2 0, 1 2, 0 0)) (a copy of the original polygon).

SELECT TREAT( Shape AS ST_Polygon ).ST_CurvePolyToPoly()
FROM SpatialShapes WHERE ShapeID = 16

The following example returns the result Polygon ((0 0, 5 0, 5 10, 0 0)) (the curve polygon converted to an equivalent polygon).

SELECT NEW ST_CurvePolygon( 'CurvePolygon(CompoundCurve((0 0, 5 10, 5 0, 0 0)))' )
                .ST_CurvePolyToPoly()

The following returns an interpolated polygon which approximates the original curve polygon.

SELECT TREAT( Shape AS ST_CurvePolygon ).ST_CurvePolyToPoly()
FROM SpatialShapes WHERE ShapeId = 24

Discuss this page in DocCommentXchange.