Getting a website is not that easy huh?
You might be wondering what else we might possibly need to do after all that. There's just one last thing. When we were coding and testing our Flask website, it was nice to use a simple database like SQLite. But SQLite is a file-based database.
This is its strength and weakness. It's a strength because while we're coding up our database and debugging, it's really useful to be able to open the SQLite file using DB Viewer and see how our data looks.
But it's also a weakness because once it's deployed with a hosting provider (like Heroku or Render) the file locations are shifted around every 24 hours or so. This means that your database might just get wiped every day. That will mean some very unhappy users. (Heroku explainer here).
So we've got to put on our big-boy/big-girl pants and upgrade our simple SQLite database to PosgreSQL, a database that can handle millions of data entries and reliably delivers data to users.
Luckily, because we used SQLAlchemy to create our Flask app, there's nothing we need to change in terms of code. We just need to set up the PostgreSQL database.
1. Create a new Postgres database from the website menu.
Next, you will see a form. All you need to do is pick a name for the database and create it.
Once you've created your database, go and find the Internal Database URL in the Info section. You might have to wait a little while until your database is created.
Afterwards, simply copy this URL. You will shortly use this as an environment variable.
Go back to your web service settings called "environment". Create an environment variable that matches the name of the key you're using in the main.py.
Paste your internal database URL as the key value. It should look something like this:
postgres://example_ig2c_user:u0E_lots_of_Symbols_here@dpg-c_more_symbols3bj85d0-a/example_ig2c
You just need to make one small modification. Change the first part from postgres to postgresql. The URI has to start with "postgresql" because this is required by SQLAlchemy:
postgresql://example_ig2c_user:u0E_lots_of_Symbols_here@dpg-c_more_symbols3bj85d0-a/example_ig2c
How does all this work? SQLite is pre-installed for all Python projects, but here we are using Postgres. The reason we can seamlessly switch from SQLite to Postgres is because we are using the psycopg package in combination with SQLAlchemy. The psycopg module is an incredibly popular PostgreSQL database adapter for Python. (You can see the psycopg package listed in the requirements.txt.)
Whoohoo! Congratulations if you got this far! Your blog should be up and running now. You've got a blank slate so register your first (admin) user and write your first blog post.
Also, check out my hosted example here: