st_convexhull function

Applies to: Databricks SQL Databricks Runtime 17.1 and above

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nota

This feature is not available on Databricks SQL Classic warehouses. To learn more about Databricks SQL warehouses, see SQL warehouse types

Returns the convex hull of the input GEOMETRY as a GEOMETRY.

Syntax

st_convexhull ( geoExpr )

Arguments

• geoExpr: A GEOMETRY value.

Returns

Returns the convex hull of the input GEOMETRY (represented as a GEOMETRY value or using a standard geospatial format) as a GEOMETRY. More precisely:

• If the input GEOMETRY is empty, then the GEOMETRY is returned as is.
• If the input GEOMETRY degenerates to a point, then that point is returned.
• If the convex hull of the input GEOMETRY degenerates to a linestring segment, which happens if all vertices in the input are collinear, that segment is returned.
• In all other cases a polygon is returned.
• If the input GEOMETRY is not empty and has M coordinates, the M coordinates are dropped.

Examples

SQL

> SELECT st_astext(st_convexhull(st_geomfromtext('POLYGON((0 0,20 0,20 10,15 5,5 10,0 25,0 0))')));
  POLYGON((0 0,0 25,20 10,20 0,0 0))

Related functions

• st_concavehull function
• st_envelope function