Database Software

Hi I am using .net 2.0. I am trying to run a database query from my .net application. I need to select the ST_geometry from the table. By using
System.Data.OracleClient or Oracle.DataAccess, I get error message "Unsupported Column Datatype".
Any suggestions what .net namespace I should be using to return the ST_Geometry field in my datatable

select a.NAME, a.ADDRESS_DETAIL, a.STREET_NAME, a.LOCALITY, a.POST_CODE
from
(select * from GIS_OWNER.POI_ALL a where
sde.st_within (a. shape, sde.st_polyfromtext ('polygon ((181262.568304515 597938.283887471,181262.568304515
737638.56328803,450608.940330592 737638.56328803,450608.940330592 597938.283887471,181262.568304515
597938.283887471))', 2))=1) p,

(select * from GIS_OWNER.DYNAMIC_COVERAGE_4 a where
sde.st_within (a. shape, sde.st_polyfromtext('polygon ((181262.568304515 597938.283887471,181262.568304515
737638.56328803,450608.940330592 737638.56328803,450608.940330592 597938.283887471,181262.568304515
597938.283887471))', 2))=1) q

where
sde.ST_intersects(p.shape,q.shape) =0;