[Sqlalchemy-tickets] Issue #3819: Enum creation doesn't respect metadata schema setting (zzzeek/sqlalchemy)

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

New issue 3819: Enum creation doesn't respect metadata schema setting
https://bitbucket.org/zzzeek/sqlalchemy/issues/3819/enum-creation-doesnt-respect-metadata

tomkcook:

Sample code:


```
#!python

from sqlalchemy import create_engine, Column, Enum, Integer, event
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy.schema import DDL

db = declarative_base()
db.metadata.schema = 'test'

engine = create_engine('postgresql://tkcook:tkcook@localhost/tkcook')

import enum

event.listen(db.metadata, 'before_create', DDL('create schema if not exists test'))

class Phase(enum.Enum):
    one = 'one'
    two = 'two'

class Test(db):
    __tablename__ = 'test_t'
    id = Column(Integer, primary_key=True)
    phase = Column(Enum(Phase, name='phase'))

db.metadata.create_all(engine)

t = Test(id = 1, phase = Phase.one)
session = sessionmaker(bind=engine)()
session.add(t)
session.commit()

```

Expected result: Schema `test` contains a table called `test_t` and a type called `phase`.

Actual result: Schema `test` contains a table called `test_t` but the type `phase` is created in schema `public`.