[Sqlalchemy-tickets] Issue #3568: Use column expressions with session.bulk_update_mappings (zzzeek/sqlalchemy)

[Fabio S. <iss...@bi...>]

New issue 3568: Use column expressions with session.bulk_update_mappings
https://bitbucket.org/zzzeek/sqlalchemy/issues/3568/use-column-expressions-with

Fabio Sussetto:

```
prize = 10
mappings = {'id': 1, 'balance': User.balance + prize}
db.session.bulk_update_mappings(User, mappings)
```

On 1.0.9 this fails with the following error:
```
can't adapt type 'BinaryExpression' [SQL: 'UPDATE "user" SET balance=%(balance)s WHERE "user".id = %(user_id)s'] [parameters: ({'user_id': 1, 'balance': <sqlalchemy.sql.elements.BinaryExpression object at 0x10d153be0>}
```

Is this supported?

Thanks!