November 2024
Intermediate to advanced
208 pages
4h 56m
French
Content preview from L'alchimie essentielle de SQLA, 2e édition
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapitre 5. Réflexion
Cet ouvrage a été traduit à l'aide de l'IA. Tes réactions et tes commentaires sont les bienvenus : translation-feedback@oreilly.com
Réflexion est une technique qui nous permet de remplir un objet SQLAlchemy à partir d'une base de données existante. Tu peux réfléchir les tables, les vues, les index et les clés étrangères. Ce chapitre explique comment utiliser la réflexion sur une base de données d'exemple.
Pour les tests, je te recommande d'utiliser la base de données Chinook. Tu peux en apprendre davantage à ce sujet à l'adresse http://chinookdatabase.codeplex.com/. Nous utiliserons la version SQLite, qui est disponible dans le dossier CH06/ du code d'exemple de ce livre. Ce dossier contient également une image du schéma de la base de données afin que tu puisses visualiser le schéma avec lequel nous travaillerons tout au long de ce chapitre. Nous commencerons par refléter une seule table.
Réflexion sur les tables individuelles
Pour notre première réflexion, nous allons générer la table Artist. Nous aurons besoin d'un objet de méta-données pour contenir les informations sur le schéma de la table réfléchie, et d'un moteur attaché à la base de données Chinook. L'exemple 5-1 montre comment configurer ces deux éléments ; le processus devrait t'être très familier maintenant.
Exemple 5-1. Mise en place de nos objets initiaux
fromsqlalchemyimportMetaData,create_enginemetadata=MetaData()engine=create_engine('sqlite:///Chinook_Sqlite.sqlite')
Cette chaîne ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.