Flask Framework Cookbook - Second Edition

How it works...

Now, let's say we modify the model of our product table to add a new field called company, as shown here:

class Product(db.Model): 
    # ... 
    # Same product model as last recipe 
    # ... 
    company = db.Column(db.String(100)) 

The result of migrate will be something like the following snippet:

    $ flask db migrate
    INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
    INFO  [alembic.runtime.migration] Will assume non-transactional     DDL.
    INFO  [alembic.autogenerate.compare] Detected added column     'product.company'     Generating <path/to/application>/flask_catalog/migrations/versions/2c08f71f9253_.py ... done 

In the preceding code, we can see that Alembic compares the new model with the database table and detects a newly added column for ...