Outils pour utilisateurs
postgresql:python
Différences
Ci-dessous, les différences entre deux révisions de la page.
| Les deux révisions précédentes Révision précédente Prochaine révision | Révision précédente | ||
|
postgresql:python [2020/07/12 07:21] marclebrun |
postgresql:python [2020/07/13 05:48] (Version actuelle) marclebrun [Requête] |
||
|---|---|---|---|
| Ligne 1: | Ligne 1: | ||
| ====== PostgreSQL avec Python 3 ====== | ====== PostgreSQL avec Python 3 ====== | ||
| - | Source: [[https://pynative.com/python-postgresql-tutorial/]] | + | Sources: |
| + | * [[https://pynative.com/python-postgresql-tutorial/]] | ||
| + | * [[https://pynative.com/python-postgresql-select-data-from-table/]] | ||
| ===== Installation de Psycopg2 ===== | ===== Installation de Psycopg2 ===== | ||
| Ligne 17: | Ligne 19: | ||
| </code> | </code> | ||
| + | ===== Connexion / Déconnexion ===== | ||
| + | |||
| + | <code python> | ||
| + | import getpass, psycopg2 | ||
| + | |||
| + | username = "postgres" | ||
| + | password = None | ||
| + | conn = None | ||
| + | |||
| + | def connect(): | ||
| + | global conn | ||
| + | | ||
| + | try: | ||
| + | conn = psycopg2.connect( | ||
| + | user = username, | ||
| + | password = password, | ||
| + | host = "localhost", | ||
| + | port = "5432", | ||
| + | database = "my_database") | ||
| + | | ||
| + | except(Exception, psycopg2.Error) as error: | ||
| + | conn = None | ||
| + | print("Error while connecting:", error) | ||
| + | |||
| + | def disconnect(): | ||
| + | global conn | ||
| + | | ||
| + | if conn: | ||
| + | conn.close | ||
| + | print("Connection is closed") | ||
| + | |||
| + | password = getpass.getpass("Password for user %s :" % username) | ||
| + | try: | ||
| + | connect() | ||
| + | if conn: | ||
| + | print("Connection OK") | ||
| + | finally: | ||
| + | disconnect() | ||
| + | </code> | ||
| + | |||
| + | ===== Requête ===== | ||
| + | |||
| + | Renvoie un objet **list** dont chaque élément est un **tuple** : | ||
| + | |||
| + | <code python> | ||
| + | cursor = conn.cursor() | ||
| + | try: | ||
| + | cursor.execute(""" | ||
| + | select id, name, price | ||
| + | from products | ||
| + | where id >= %s | ||
| + | order by id; | ||
| + | """, (id,)) | ||
| + | | ||
| + | rows = cursor.fetchall() | ||
| + | print(type(rows)) | ||
| + | | ||
| + | for row in rows: | ||
| + | print(type(row)) | ||
| + | print(row) | ||
| + | | ||
| + | finally: | ||
| + | cursor.close() | ||
| + | </code> | ||
| + | |||
| + | Exemple de résultat : | ||
| + | |||
| + | <code> | ||
| + | <class 'list'> | ||
| + | <class 'tuple'> | ||
| + | (5, 'Bananes', Decimal('3.76')) | ||
| + | <class 'tuple'> | ||
| + | (6, 'Oranges', Decimal('6.20')) | ||
| + | </code> | ||
postgresql/python.1594538504.txt.gz · Dernière modification: 2020/07/12 07:21 par marclebrun
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