[Sqlalchemy-tickets] Issue #3861: Automapping certain sqlalchemy indexes produces duplicate representation (zzzeek/sqlalchemy)

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

New issue 3861: Automapping certain sqlalchemy indexes produces duplicate representation
https://bitbucket.org/zzzeek/sqlalchemy/issues/3861/automapping-certain-sqlalchemy-indexes

Rob Salmond:

I'm not really sure what's going on here but for this particular schema after reflection via the automapper the indexes are duplicated. If you remove anything from the table definitions the duplication goes away.

```
$ cat repro.sql 
CREATE TABLE "users" ("id" integer not null primary key autoincrement not null, "slug" varchar(150) not null, "email" varchar(254) not null);
CREATE UNIQUE INDEX users_email_unique on "users" ("email");
CREATE TABLE "refreshtokens" ("id" integer not null primary key autoincrement, "user_id" integer not null, foreign key("user_id") references "users"("id"));
CREATE UNIQUE INDEX users_slug_unique on "users" ("slug");

$ sqlite3 repro.db ".read repro.sql"

$ cat repro.py 
from sqlalchemy.ext.automap import automap_base
from sqlalchemy.orm import Session
from sqlalchemy import create_engine

Base = automap_base()
engine = create_engine("sqlite:///repro.db")
Base.prepare(engine, reflect=True)
users = Base.metadata.tables.get('users')
print(users.indexes)

$ python repro.py
set([Index('users_slug_unique', Column('slug', VARCHAR(length=150), table=<users>, nullable=False), unique=True), Index('users_email_unique', Column('email', VARCHAR(length=254), table=<users>, nullable=False), unique=True), Index('users_email_unique', Column('email', VARCHAR(length=254), table=<users>, nullable=False), unique=True), Index('users_slug_unique', Column('slug', VARCHAR(length=150), table=<users>, nullable=False), unique=True)])

$ pip freeze
PyMySQL==0.7.9
SQLAlchemy==1.1.4

$ python --version
Python 2.7.9

$ sqlite3 --version
3.8.7.1 2014-10-29 13:59:56 3b7b72c4685aa5cf5e675c2c47ebec10d9704221
```