st_zmax
function
Applies to: Databricks SQL
Databricks Runtime 17.1 and above
Preview
This feature is in Public Preview.
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 maximum Z coordinate of the input GEOMETRY
value, or NULL
if the geometry is empty or does not have a Z coordinate.
Syntax
st_zmax ( geoExpr )
Arguments
geoExpr
: AGEOMETRY
value.
Returns
A value of type DOUBLE
, equal to the maximum Z coordinate of the input GEOMETRY
value.
The function returns NULL
if the input is NULL
or if the geometry is empty or does not have a Z coordinate.
Examples
SQL
-- Returns the maximum Z coordinate of a non-empty geometry with a Z coordinate.
> SELECT st_zmax(st_geomfromtext('LINESTRING Z (10 34 -1,44 57 -2,30 24 -5)'));
-1.0
-- Returns `NULL` for a non-empty geometry without a Z coordinate.
> SELECT st_zmax(st_geomfromtext('LINESTRING(10 34,44 57,30 24)'));
NULL