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Creating Our Book Database
8:04Create a model for your book database using a CSV of books as your template. Import your model into your main app file.
It's time to create our database.
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Let's start with our imports at the top.
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From sqlalchemy import, and
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we're going to do create_engine,
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Column, Integer, String, and
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Date cuz we'll need that for
the published date column.
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And since this is getting a little long,
I'm gonna put these in parentheses so
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then I can split them
onto multiple lines here.
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There we go.
Okay, now we need to go
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from sqlalchemy.ext.declarative
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import declarative_base.
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And then from sqlalchemy.orm
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import sessionmaker.
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Awesome, now we can create our engine
with a database named books.db.
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Engine = create_engine, and
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we'll need sqlite:///books.db,
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and then I'm gonna set echo to false.
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Once again, if you want echo to be true so
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that you have those extra messages in
the console, that is totally up to you.
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After our engine, let's do our session.
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We need two session variables,
first one with a capital S.
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And that's going to be
equal to sessionmaker, and
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we're going to bind it to our engine,
which is our database.
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And then we need to do session, which is
going to call Session with a capital S.
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And then the last one we need
is Base with a capital B.
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And that's going to be equal
to our declarative_base.
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Next up goes our model,
let's add a couple spaces.
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And let's do class, and let's call
it Book, and let's pass in our Base.
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And then we'll need a table name,
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__tablename__ =, and let's call it books.
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And now we're on to our columns.
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The first column will be our id.
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So each book will have a unique
id value attached to it.
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It's going to be an integer column, and
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it's going to be our primary key,
primary_key = True.
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Awesome, the next column will be for
the book title.
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So title = Column, and
I'm going to do a string that says Title.
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And then this column is
going to be all strings.
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You're probably wondering why I
passed in a string to this column.
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This string is how the name of this
column will look in the database.
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Instead of title,
it'll be this Title with a capital T.
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This isn't required, but it can make your
columns look a bit neater, in my opinion.
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Next step will be author,
and that'll be a Column, and
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I'll do Author as title, and
it will also be a String.
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And then published date,
published_date = Column,
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and I'm just gonna call this Published,
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and this is going to be a Date.
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And the last one is going to be price,
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it's gonna be equal to Column,
which is going to be an Integer.
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And oops, I forgot,
I also want to call it Price, there we go.
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And don't forget to save, great.
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Let's also add that dunder repr method,
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def __repr__,
it will take self because this is a class.
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And then it's going to
return a formatted string
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that's going to have our
book information in it.
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So let's do Title, and then self.title.
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And then we're going to need the author,
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that's going to be self.author.
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Published with
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self.published_date.
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And then we need Price with
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self.price, and save.
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Perfect, over in app.py,
let's import our models.
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And instead of just running import models,
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we're going to import
the specific pieces we need.
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So from models import and
I'm gonna put these in
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parentheses cuz we're gonna
have a couple of them.
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We're going to need Base and session, and
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our Book class, and engine.
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Then I'm gonna split these
into two lines here.
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Okay, at the bottom,
let's add a few spaces.
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And let's put in our dunder name.
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__name__ = '__main__'.
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Okay, inside of here, we can create our
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database with Base.metadata.create_all,
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and pass in engine, save.
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Sweet, our model and
database are all ready to go.
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You can run Python or python3 app.py, and
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there's our database,
except I spelled it wrong.
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I did boks, I guess,
[LAUGH] instead of books.
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So if you're like me and you made that
mistake, you can fix your spelling,
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save the file, and
then you can just delete this file.
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Move to Trash, and then run python3 app.py
again, and it'll recreate your database.
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There we go, books.db, that looks better.
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Now that we've added all of this code,
it's time to add it to our repo.
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So git add, and
then everything that we've done so far.
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And then we're going to do git commit -m,
and
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let's say we added our database model.
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Hit Enter, and you can see, it shows
we have three files that have changed.
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models.py, we had some rewrites to it,
and we created books.db.
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And we also had some revisions to app.py.
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And then we need to push it up
with git push origin master.
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Perfect, let's click on our GitHub again,
refresh.
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You can see our books.db is now here.
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And if I click into our models.py,
there is our model we created.
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Amazing work, Pythonistas.
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