[Sqlalchemy-tickets] Issue #3166: autoincrement should not be True for non-integer primary key (zzzeek/sqlalchemy)

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

New issue 3166: autoincrement should not be True for non-integer primary key
https://bitbucket.org/zzzeek/sqlalchemy/issue/3166/autoincrement-should-not-be-true-for-non

lieryan:

The behavior of autoincrement attribute is misleading when the primary key is not an integer primary key.

Test case:

```
#!python
from sqlalchemy import Column, String
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()
class Table(Base):
    __tablename__ = 'table'
    code = Column(String(50), primary_key = True)

table = Base.metadata.tables['table']
pk_column = table.primary_key.columns['code']
assert not pk_column.autoincrement

```