ST_NumInteriorRings - Amazon Redshift
SyntaxArgumentsReturn typeExamples

Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the blog post .

ST_NumInteriorRings

ST_NumInteriorRings returns the number of rings in an input polygon geometry.

Syntax

ST_NumInteriorRings(geom)

Arguments

geom

A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type.

Return type

INTEGER

If geom is null, then null is returned.

If geom is not a polygon, then null is returned.

Examples

The following SQL returns the number of interior rings in the input polygon. 

SELECT ST_NumInteriorRings(ST_GeomFromText('POLYGON((0 0,100 0,100 100,0 100,0 0),(1 1,1 5,5 1,1 1),(7 7,7 8,8 7,7 7))'));

 st_numinteriorrings
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