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st_numgeometries function

Applies to: check marked yes Databricks SQL check marked yes Databricks Runtime 17.1 and above

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Returns the number of geometries in the input GEOMETRY value.

Syntax

st_numgeometries ( geoExpr )

Arguments

  • geoExpr: A GEOMETRY value.

Returns

A value of type INT, representing the number of geometries in the input GEOMETRY value.

The function returns NULL if the input is NULL.

Examples

SQL
-- Returns the number of geometries in a non-empty multipoint geometry.
> SELECT st_numgeometries(st_geomfromtext('MULTIPOINT(10 34,44 57,EMPTY)'));
3
-- Returns the number of geometries in an empty polygon geometry.
> SELECT st_numgeometries(st_geomfromtext('POLYGON EMPTY'));
0
-- Returns the number of geometries in a non-empty polygon geometry.
> SELECT st_numgeometries(st_geomfromtext('POLYGON((0 0,1 0,1 1,0 1,0 0))'));
1
-- Returns the number of geometries in a non-empty geometry collection.
> SELECT st_numgeometries(st_geomfromtext('GEOMETRYCOLLECTION(LINESTRING EMPTY,GEOMETRYCOLLECTION(POINT(1 2),POLYGON((0 0,1 0,0 1,0 0))))'));
2