[Zope3-dev] Psycopgda adapter, should _conv_str do NULL check?

[Carroll Kong]

In psycopgda module rev 27872, adapter.py ~line 266

The original code just converts strings passed to _conv_string into unicode.

def _conv_string(str):
    return str.decode(PG_ENCODING)

However, if I have a NULL field in the database, then str.decode fails with
AttributeError: 'NoneType' object has no attribute 'decode'

This isn't the same as a '' string (in which case the decode would work), or
at least my psycopgda driver (1.1.14 ) and postgresl version (7.4.1) didn't
seem to believe so.  (I had an optional field and it was empty before I put
on constraints to add default values).

I suppose you could argue that one should always use strong default values
into the database.  I am not as familiar with the code, but I added this to
psycopgda's adapter.py.

def _conv_string(str):
    if str:
        return str.decode(PG_ENCODING)
    else:
        return None

Not sure if that's going to cause problems or not.  My prelim testing seems
to show it will work, or I could just always use default values so there are
no NULL optional fields.



- Carroll Kong