st_numgeometries function
Applies to: 
Databricks SQL Databricks Runtime 17.1 and above
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注記
This feature is not available on Databricks SQL Classic warehouses. To learn more about Databricks SQL warehouses, see SQL warehouse types
Returns the number of geometries in the input GEOMETRY value.
Syntax
st_numgeometries ( geoExpr )
Arguments
geoExpr: AGEOMETRYvalue.
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