[Sqlalchemy-tickets] Issue #4183: Using func.sum(BinaryExp), returns boolean instead of a sum (wasn't the case in 1.1.12) (zzzeek/sqlalchemy)

[Bastien G. <iss...@bi...>]

New issue 4183: Using func.sum(BinaryExp), returns boolean instead of a sum (wasn't the case in 1.1.12)
https://bitbucket.org/zzzeek/sqlalchemy/issues/4183/using-funcsum-binaryexp-returns-boolean

Bastien Gérard:

Hi,
First of all, we are using MySQL 5.6

After switching from sqlalchemy 1.1.12 to 1.2.2, we observed that one of our test failed.

In fact the following scenario should return a RowProxy with the values being the sum but the values are boolean instead.

```
#!python
from sqlalchemy import select
from sqlalchemy.sql.functions import func

engine, tbl, col = ...
sel = select([func.sum(col.is_(None))])
print sel # SELECT sum(smart_result.signal_predicted IS NULL) AS sum_1 FROM smart_result
row = engine.execute(sel).fetchone()
print dict(row) # {u'sum_1': True}

# And if I execute it manually:
r = engine.execute('SELECT sum(smart_result.signal_predicted IS NULL) AS sum_1 FROM smart_result')
print r.fetchall() # [(Decimal('120'),)]
```

I don't know if it could be related but by printing row._key_map, I see references to "<function sqlalchemy.cprocessors.int_to_boolean>".