Trying to query using the st_pointonsurface funtion in SDE

[chris_cawser]

Hi,

Trying to get the st_pointonsurface function working in my sql query.

Using ArcGIS 10.1 and sde in an Oracle 11g database.

Here's my code:

SELECT sde.st_astext(sde.st_pointonsurface(p.SHAPE))
FROM CD31_ENG_2017_PCL_TEMP p;

I get this error message:

ORA-20003: ST_Geometry type must be an ST_LINESTRING type.
ORA-06512: at "SDE.ST_GEOMETRY_OPERATORS", line 1620

The help says I need a polgon input to the function, so the ST_LINESTRING type is puzzling.

I have two polygons in feature class. Other functions work on the objects, such as ST_CENTROID,  but not ST_POINTONSURFACE.

Any help really appreciated.

Thank You.