How to query a table that contains sql_variant in sqlalchemy

Question

I am trying to query an instance of a mapped class with sqlalchemy that contains a column with a sql_variant data type. However, when executing my query, I get the following error:

sqlalchemy.exc.ProgrammingError: (pyodbc.ProgrammingError) ('ODBC SQL type -150 is not yet supported.  column-index=3  type=-150', 'HY106')

My mapped class goes like this:

class ParamValue(Base):
    __table__ = Table('param', autoload=True)

It contains 4 columns:

id (PK, int, not null)
param_set_id (FK, int, not null)
param_id (FK, int, not null)
value (sql_variant, null)

And my query looks like this (simple query):

session.query(ParamValue).all()

Anything could help, thanks