Survey models

[katrinacrisostomo]

not wip anymore, ready for code review

Database schema

[chrisjluc]

@dinahshi we fixed the tests. By looking at the schema.rb and making sure the associations line up in the model. Kind of a mess of changes. We then changed the column ids because it was complaining about not having question_id vs questions_id etc.

[dinahshi]

Noticing some commits that only affect schema.rb and some with migrations and no changes to schema.rb. This is bad because it messes with our mental model of the db vs what it actually looks like which could lead to having to drop the db to reset. Every migration should be paired with a schema.rb update and the schema doc should not be changed except through a migration.

[chrisjluc]

Here is the migration commit that reflects changes in the schema commit. We deleted the tables and ran rake db:migrate and it produced the same schema.rb

[dinahshi]

I dropped my local db, recreated, and ran migrations and had inconsistencies with schema.rb - we should try to let the framework handle this for us rather than manually checking. Also rather than editing existing migrations, we should create new migrations. Not that big of a deal in this case since the migrations haven't been deployed but good habit to get into.

[chrisjluc]

@dinahshi and I clarified some confusions within the database models and our mental models.

So we don't want question_orders to be associated directly with a question. Instead, a question should have many response choices which point to the question_order, which in turn points to the next question. This allows for simplicity by following one branch of execution no matter what.

Therefore, execution is done by looking at the response choices and from there looking at the associated question order.

Previously question points to question_order and if it's not conditional we use this direct relationship, but if it's a conditional question we look at the response choice and go to the question order from there.

[chrisjluc]

I think we pluralized things when they should have been singular and vice versa. Which caused some column names to be named wrong in the tables.

i.e. the framework was looking for question_id but it didn't exist because the column was named questions_id in the table. That's why we changed the migration and schema and we thought it created the same schema.rb.

We did something wrong there if the schema.rb is different

[katrinacrisostomo]

OKAY LGTM 👍 @dinahshi, @chrisjluc ?

[chrisjluc]

LGTM