st_zmin 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 minimum Z coordinate of the input GEOMETRY, or NULL if the geometry is empty or does not have a Z coordinate.
Syntax
st_zmin ( geoExpr )
Arguments
geoExpr: AGEOMETRYvalue.
Returns
A value of type DOUBLE, minimum Z coordinate of the input GEOMETRY.
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 minimum Z coordinate of a non-empty geometry with a Z coordinate.
> SELECT st_zmin(st_geomfromtext('LINESTRING Z (10 34 -1,44 57 -2,30 24 -5)'));
-5.0
-- Returns `NULL` for a non-empty geometry without a Z coordinate.
> SELECT st_zmin(st_geomfromtext('LINESTRING(10 34,44 57,30 24)'));
NULL