Query.get_count produces SQL that is invalid for DB2

[Paul Wujek]

This bug occurs in db/models/sql/query.py

In function get_count lines 5 and 6 are:

        obj.add_annotation(Count('*'), alias='__count', is_summary=True)
        number = obj.get_aggregation(using, ['__count'])['__count']

Code produced looks like:

SELECT COUNT(*) AS __count FROM MYTABLE

Error Returned:

[SQL0104] Token _ was not valid. Valid tokens: <IDENTIFIER>. [SQL State=42601, DB Errorcode=-104]

Cause:
Underscore is not valid as a beginning character for a token in DB2.

Suggested Solution:

Do not use '__count' as a token in the 5th and 6th lines of get_count.
Instead use a token name that does not begin with '_' (Underscore).

[Simon Charette]

Is there anyway for the DB2 adapter to quote such identifiers? Would that make them valid?

For example, the MySQL backend's quote_name wraps names in backtips ` resulting the in the following query

SELECT COUNT(*) AS `__count` FROM `table`

[Tim Graham]

Closing as wontifx absent justification that the problem can't be fixed in the DB2 backend.