data type inconsistency

I am using the cl-odbc layer to connect to an Oracle database.  ( I must
use this, rather than cl-oracle, because I am using the same code to
connect to MSSQL databases via FreeTDS as well.)  I am not using clsql's
MOP functionality.  Instead, I am simply calling execute-query, and
dealing with the resulting lists myself.

If I perform a SELECT query against an ordinary table, all values come
back as strings.  But if I query a pipelined table function, the data
types of the various atoms match the types defined by the function's
accompanying type object.

Can I get queries against ordinary tables to produce the correct types
using the ODBC interface?  This is my question.