Demonstration of a curious discrepancy between MySQL and SQLite when using file uploads with Flask-Admin and Flask-SQLAlchemy.

openclipart_hector_gomez_landscape.png

output.txt

.E
======================================================================
ERROR: test_upload_works (test_flask_admin_testcase.PictureTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_flask_admin_testcase.py", line 118, in test_upload_works
    'path': (test_image_path, test_image_name),
  File "/path/to/env/lib/python2.7/site-packages/werkzeug/test.py", line 784, in post
    return self.open(*args, **kw)
  File "/path/to/env/lib/python2.7/site-packages/flask/testing.py", line 108, in open
    follow_redirects=follow_redirects)
  File "/path/to/env/lib/python2.7/site-packages/werkzeug/test.py", line 742, in open
    response = self.run_wsgi_app(environ, buffered=buffered)
  File "/path/to/env/lib/python2.7/site-packages/werkzeug/test.py", line 659, in run_wsgi_app
    rv = run_wsgi_app(self.application, environ, buffered=buffered)
  File "/path/to/env/lib/python2.7/site-packages/werkzeug/test.py", line 867, in run_wsgi_app
    app_rv = app(environ, start_response)
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/path/to/env/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/path/to/env/lib/python2.7/site-packages/flask_admin/base.py", line 68, in inner
    return self._run_view(f, *args, **kwargs)
  File "/path/to/env/lib/python2.7/site-packages/flask_admin/base.py", line 359, in _run_view
    return fn(self, *args, **kwargs)
  File "/path/to/env/lib/python2.7/site-packages/flask_admin/model/base.py", line 1585, in create_view
    if self.validate_form(form):
  File "/path/to/env/lib/python2.7/site-packages/flask_admin/model/base.py", line 1037, in validate_form
    return validate_form_on_submit(form)
  File "/path/to/env/lib/python2.7/site-packages/flask_admin/helpers.py", line 65, in validate_form_on_submit
    return is_form_submitted() and form.validate()
  File "/path/to/env/lib/python2.7/site-packages/wtforms/form.py", line 310, in validate
    return super(Form, self).validate(extra)
  File "/path/to/env/lib/python2.7/site-packages/wtforms/form.py", line 152, in validate
    if not field.validate(self, extra):
  File "/path/to/env/lib/python2.7/site-packages/wtforms/fields/core.py", line 200, in validate
    stop_validation = self._run_validation_chain(form, chain)
  File "/path/to/env/lib/python2.7/site-packages/wtforms/fields/core.py", line 220, in _run_validation_chain
    validator(form, self)
  File "/path/to/env/lib/python2.7/site-packages/flask_admin/contrib/sqla/validators.py", line 37, in __call__
    .filter(self.column == field.data)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2473, in one
    ret = list(self)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2516, in __iter__
    return self._execute_and_instances(context)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2531, in _execute_and_instances
    result = conn.execute(querycontext.statement, self._params)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/sql/elements.py", line 323, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1010, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception
    exc_info
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1139, in _execute_context
    context)
  File "/path/to/env/lib/python2.7/site-packages/sqlalchemy/engine/default.py", line 450, in do_execute
    cursor.execute(statement, parameters)
InterfaceError: (sqlite3.InterfaceError) Error binding parameter 0 - probably unsupported type. [SQL: u'SELECT picture.id AS picture_id, picture.name AS picture_name, picture.path AS picture_path \nFROM picture \nWHERE picture.path = ?'] [parameters: (<FileStorage: u'openclipart_hector_gomez_landscape.png' ('image/png')>,)]

----------------------------------------------------------------------
Ran 2 tests in 0.170s

FAILED (errors=1)

requirements.txt

CherryPy==3.8.0
Flask==0.10.1
Flask-Admin==1.2.0
Flask-SQLAlchemy==2.0
Jinja2==2.7.3
MarkupSafe==0.23
MySQL-python==1.2.5
Pillow==2.9.0
PyYAML==3.11
SQLAlchemy==1.0.6
WTForms==2.0.2
Werkzeug==0.10.4
argparse==1.3.0
glob2==0.4.1
itsdangerous==0.24
ordereddict==1.1
pip-tools==0.3.6
six==1.9.0
wsgiref==0.1.2

test_flask_admin_testcase.py

#!/usr/bin/env python

# (c) 2014 Digital Humanities Lab, Faculty of Humanities, Utrecht University
# Author: Julian Gonggrijp, j.gonggrijp@uu.nl

# Prerequisites:
# Create a MySQL database 'example' with user 'example' and no password.
# Create a Python 2.7 virtualenv in which you install the requirements.

# In order to run the application with the built-in server, run
# python test_flask_admin_testcase.py
# and visit 127.0.0.1:5000/admin with your browser.
# Uploading of images should work perfectly fine in this case.

# In order to run the test suite, run
# python -m unittest test_flask_admin_testcase
# You should get something similar to the contents of output.txt.

import os
import os.path as op
from tempfile import mkdtemp
from shutil import rmtree
from unittest import TestCase

from flask import Flask, current_app
from flask.ext.admin import Admin, form
from flask.ext.sqlalchemy import SQLAlchemy
from flask.ext.admin.contrib.sqla import ModelView


db = SQLAlchemy()


class Picture(db.Model):
    id   = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(40), nullable=False)
    path = db.Column(db.String(50), unique=True, nullable=False)
    

class PictureView(ModelView):
    column_list = ('name',)
    form_columns = ('name', 'path')
    form_overrides = {
        'path': form.FileUploadField,
    }
    form_args = {
        'path': {
            'label': 'File',
            'base_path': lambda: current_app.instance_path,
            'allowed_extensions': ('jpg', 'jpeg', 'png'),
        }
    }

    def __init__(self, session, name='Picture', **kwargs):
        super(PictureView, self).__init__(Picture, session, name, **kwargs)


def create_admin(app):
    admin = Admin(name='Example')
    admin.add_view(PictureView(db.session))
    admin.init_app(app)


def create_app(config_obj, instance=None):
    app = Flask(__name__, instance_path=instance)
    app.config.from_object(config_obj)

    db.init_app(app)
    db.create_all(app=app)
    create_admin(app)

    return app


class Configuration(object):
    SQLALCHEMY_DATABASE_URI = 'mysql://example@localhost/example?charset=utf8&use_unicode=0'
    SECRET_KEY = 'psiodfnvpsdojfnvpaosihrgt'


if __name__ == '__main__':
    app = create_app(Configuration)
    app.debug = True
    app.run()


class FixtureConfiguration(Configuration):
    SQLALCHEMY_DATABASE_URI = 'sqlite://'
    TESTING = True


class PictureTestCase(TestCase):
    def setUp(self):
        super(PictureTestCase, self).setUp()
        tmpdir = mkdtemp('example_instance')
        self.app = create_app(FixtureConfiguration, tmpdir)
        self.client = self.app.test_client()

    def tearDown(self):
        db.drop_all(app=self.app)
        rmtree(self.app.instance_path)
        super(PictureTestCase, self).tearDown()

    def request_context(self):
        return self.app.test_request_context()

    def test_picture_exists(self):
        pic = Picture(name='Test', path='test/test.jpeg')
        with self.request_context():
            db.session.add(pic)
            db.session.commit()
            first = db.session.query(Picture).first()
        self.assertEqual(pic.id, 1)
        self.assertEqual(first, pic)

    def test_upload_works(self):
        test_image_name = 'openclipart_hector_gomez_landscape.png'
        tests_dir = op.dirname(__file__)
        test_image_path = op.join(tests_dir, test_image_name)
        with self.client as c:
            c.post('/admin/picture/new/', data={
                'name': 'testimage',
                'path': (test_image_path, test_image_name),
            })
            images = Picture.query.all()
        self.assertEqual(len(images), 1)
        self.assertEqual(images[0].path, test_image_name)
        directory = os.listdir(self.app.instance_path)
        self.assertEqual(len(directory), 1)
        self.assertIn(test_image_name, directory)

I have the same issue. What was the fix?