st_z function
Applies to: 
Databricks SQL Databricks Runtime 17.1 and above
Preview
This feature is in Public Preview.
nota
This feature is not available on Databricks SQL Classic warehouses. To learn more about Databricks SQL warehouses, see SQL warehouse types
Returns the Z coordinate of the input point GEOMETRY, or NULL if the point is empty or does not have a Z coordinate.
Syntax
st_z ( geoExpr )
Arguments
geoExpr: AGEOMETRYvalue.
Returns
A value of type DOUBLE, Z coordinate of the input point GEOMETRY.
The function returns NULL if the input is NULL or if the point is empty.
Error conditions
- If the value of
geoExpris not a point, the function returns ST_INVALID_ARGUMENT.INVALID_TYPE.
Examples
SQL
-- Returns the Z coordinate of a non-empty point geometry with a Z coordinate.
> SELECT st_z(st_geomfromtext('POINT Z (1 2 3)'));
3.0
-- Returns the Z coordinate of a non-empty point geometry without a Z coordinate.
> SELECT st_z(st_geomfromtext('POINT M (2 3 4)'));
NULL
-- Returns `NULL` for an empty point geometry.
> SELECT st_z(st_geomfromtext('POINT ZM EMPTY'));
NULL