[ Is there a Database independent way with SQLAlchemy to query filtered by "None"/"NaN"? ]
The following code is DB specific:
import sqlalchemy # ... ergebnis = session.query( my_object.attr1).filter(sa.and_( my_object.attr2 != 'NaN')).all() # PostgreSQL """ my_object.attr2 != None)).all() # sQLite """
With PostgreSQL it is "'NaN'", with SQLite "None" (without single quotes). Is there a SQLAlchemy-way to do this backend independant?
If you want to compare against the
'NaN' ("not a number") float value, then do an explicit cast to float:
float('NaN'). In this case SQLAlchemy should do the same conversion.