Steps in writing an SQLAlchemy query

Start with something like this:

   result = models.

What table do we want to query?  Pizza?

   result = models.Pizza.

And we're writing a query... so:

   result = models.Pizza.query.

And do we want everything?

   result = models.Pizza.query.all()

Or do we just want one thing:

   result = models.Pizza.query.filter_by(something=something_else).first()

And what do we actually want?  name="Hawaiian", id=3, etc.  For example: SELECT * FROM Pizza WHERE name="Hawaiian";

   result = models.Pizza.query.filter_by(name="Hawaiian").

And do we now want all pizzas called Hawaiian or just the first one?

   result = models.Pizza.query.filter_by(name="Hawaiian").all()

 or

   result = models.Pizza.query.filter_by(name="Hawaiian").first()

Note: .first() queries will return an object with the results for a single entry, while .all() queries will return a list of those objects - even if there are no results (in which case an empty list will be returned).  If no result is found for a .first() query then None will be returned.  There is a special version of .first() to throw a 404 error for this case (which you often want to do:

   result = models.Pizza.query.filter_by(name="Hawaiian").first_or_404()

Result is a terrible name for a variable, of course - a better name in this case would be pizza, or pizzas.

   pizza = models.Pizza.query.filter_by(name="Hawaiian").first_or_404()

And you would access the members of the result something like this:

   print(pizza.name) or {{ pizza.name }}