st_dimension function

Applies to: Databricks SQL Databricks Runtime 17.1 and above

Preview

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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 topological dimension of the 2D projection of the GEOMETRY value.

Syntax

st_dimension ( geoExpr )

Arguments

• geoExpr: A GEOMETRY value.

Returns

Returns the topological dimension of the 2D projection of the input GEOMETRY value. The expression returns:

• 0, if the input GEOMETRY value is a point or a multipoint.
• 1, if the input GEOMETRY value is a linestring or a multilinestring.
• 2, if the input GEOMETRY value is a polygon or a multipolygon.
• 0, if the input GEOMETRY value is an empty geometry collection.
• The maximum dimension of elements of the collection, if the input is a non-empty geometry collection.

Examples

SQL

> SELECT st_dimension(st_geomfromtext('MULTIPOINT(EMPTY,-1 0,EMPTY)'));
  0

> SELECT st_dimension(st_geomfromtext('LINESTRING(-1 0,0 -1,1 0,0 1,-1 0)'));
  1

> SELECT st_dimension(st_geomfromtext('MULTIPOLYGON(EMPTY,((-1 0,0 -1,1 0,0 1,-1 0)))'));
  2

> SELECT st_dimension(st_geomfromtext('GEOMETRYCOLLECTION EMPTY'));
  0

Related functions

• st_geometrytype function
• st_ndims function