[Sqlalchemy-tickets] Issue #4280: constant enum values fails with mysql driver (zzzeek/sqlalchemy)

[VA <iss...@bi...>]

New issue 4280: constant enum values fails with mysql driver
https://bitbucket.org/zzzeek/sqlalchemy/issues/4280/constant-enum-values-fails-with-mysql

VA:

I have a table with an Integer column. When filtering on this column using a Python int value, I only get rows matching the integer, which is expected. However, if I filter on the same column with an IntEnum value, I do not get any rows at all when using the mysql driver. It works properly using the sqlite driver though.

Attached is a sample source file creating a basic table and doing basic filters. Switching between the 2 drivers is a matter of commenting one line, yet the behavior is completely different.

Here are excerpts from the attached file:

* A working line with both drivers:

```
#!python

print(session.query(Simple).filter(Simple.stuff == 1).all())
```

* Line not working with mysql:

```
#!python

print(session.query(Simple).filter(Simple.stuff == My.a).all())
```

When using mysql, I get this warning:

```
#!python

/usr/lib/python2.7/dist-packages/sqlalchemy/engine/default.py:508: Warning: (1292L, "Truncated incorrect DOUBLE value: 'My.a'")

```

So it seems the mysql driver is attempting stringification of a value which is an int (IntEnum inherits int) and fails.