Query returns different data when using MySQL and SQLite

When I query the following model with SQLAlchemy I don't get the expected result.

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True)

    def __repr__(self):
        return '<User %r>' % self.username

      

        
        
        
      

    

I created a MySQL table directly and then passed some data:

mysql> CREATE TABLE "users" (id INTEGER, username VARCHAR(64));

mysql> select * from users;  
+------+-------------+---------+  
| id   | username    | role_id |  
+------+-------------+---------+  
| NULL | yzxu        | NULL    |   
| NULL | after       | NULL    |  
+------+-------------+---------+  

      

        
        
        
      

    

When using MySQL, SQLAlchemy query returns None

.

>>> User.query.filter_by(username='after').all()
[None]

      

        
        
        
      

    

The correct username is returned when using SQLite.

>>> db.create_all()
>>> db.session.add(User(username='after'))
>>> db.session.commit()
>>> User.query.filter_by(username='after').all()
[<User u'after'>]