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st_numinteriorrings function

Applies to: check marked yes Databricks Runtime 17.3 and above

Preview

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Returns the number of interior rings of the input polygon.

Syntax

st_numinteriorrings ( geoExpr )

Arguments

  • geoExpr: A GEOGRAPHY or GEOMETRY value.

Returns

An INTEGER that specifies the count of interior rings in the input polygon.

Notes

The function returns NULL if the input is NULL.

Error conditions

Examples

SQL
-- Example taking an empty 2D polygon GEOMETRY.
> SELECT ST_NumInteriorRings(ST_GeomFromText('POLYGON EMPTY', 4326));
0
-- Example taking a 3DZ polygon GEOGRAPHY with one non-empty ring.
> SELECT ST_NumInteriorRings(ST_GeogFromText('POLYGON Z ((0 0 6,1 0 6,1 1 8,0 1 6,0 0 6))'));
0
-- Example taking a 4D polygon GEOMETRY with two rings.
> SELECT ST_NumInteriorRings(ST_GeomFromText('POLYGON ZM ((0 0 111 -11,10 0 222 -22,0 10 333 -33,0 0 444 -44),(1 1 555 -55,4 1 666 -66,1 4 777 -77,1 1 888 -88))', 4326));
1
-- Example taking a 3DM polygon GEOGRAPHY with three rings.
> SELECT ST_NumInteriorRings(ST_GeogFromText('POLYGON M ((0 0 1,10 0 2,0 10 3,0 0 1),(1 1 2,2 1 3,1 2 4,1 1 2),(3 3 3,3 2 4,2 3 5,3 3 3))'));
2