Let's discuss the process of DELETING data from the database. Return to our Python Console and give the delete query a try. Deleting is a simple process – you just need to invoke the database object and use the delete() method instead of add(). Then, pass the object you want to delete.

If you've closed your terminal or Python Console, don't worry. You can simply import db, Recipe, app to get back on track.

recipe = Recipe.query.get(4)
db.session.delete(recipe)
# we haven't commit this change yet.
db.session.commit()
# now it should work now and its gone.
Recipe.query.all()

It's pretty much for deleting just to know id.