ST_IsClosed method

Tests if the ST_MultiCurve value is closed. A curve is closed if the start and end points are coincident. A multicurve is closed if it is non-empty and has an empty boundary.

Note

By default, ST_IsClosed 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.

Syntax

multicurve-expression.ST_IsClosed()

Returns

Standards and compatibility

Example

The following returns the result 0 because the boundary of the multicurve has two points.

SELECT NEW ST_MultiCurve( 'MultiCurve((0 0, 1 1))' ).ST_IsClosed()

The following returns all rows in multicurve_table that have closed geometries. This example assumes the geometry column has type ST_MultiCurve or ST_MultiLineString.

SELECT * FROM multicurve_table WHERE geometry.ST_IsClosed() = 1

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