Working with PostgreSQL Using Psycopg2 in Python
Psycopg2 is a popular PostgreSQL adapter for Python. It provides efficient and secure interaction with PostgreSQL databases, supporting advanced features such as transactions, connection pooling, and asynchronous operations.
1. Installation
Install Psycopg2 using pip:
pip install psycopg2
2. Connecting to PostgreSQL
Establish a connection to the PostgreSQL database using the connect() method:
import psycopg2
conn = psycopg2.connect(
dbname="your_database",
user="your_username",
password="your_password",
host="localhost",
port="5432"
)
print("Connected successfully")
3. Executing Queries
a. Create a Cursor
Cursors allow you to execute queries:
cur = conn.cursor()
b. Execute a Query
cur.execute("SELECT * FROM table_name")
rows = cur.fetchall()
for row in rows:
print(row)
c. Commit Changes (if needed)
For INSERT, UPDATE, or DELETE queries:
Copy code
cur.execute("INSERT INTO table_name (column1, column2) VALUES (%s, %s)", (value1, value2))
conn.commit()
4. Error Handling
Handle exceptions to manage database errors gracefully:
try:
conn = psycopg2.connect(...)
cur = conn.cursor()
cur.execute("SELECT * FROM table_name")
except psycopg2.Error as e:
print("Database error:", e)
finally:
cur.close()
conn.close()
5. Using Connection Pooling
To improve performance, use a connection pool with psycopg2.pool:
from psycopg2.pool import SimpleConnectionPool pool = SimpleConnectionPool(1, 10, dsn="...") conn = pool.getconn()
6. Advanced Features
Feature Description Example Asynchronous Queries Use psycopg2 with async operations. psycopg2.connect(async_=True) Prepared Statements Optimize performance for repetitive queries. PREPARE and EXECUTE SQL commands Transaction Control Manage database transactions explicitly. conn.commit() and conn.rollback()Additional Notes:
All PostgreSQL Questions, Answers, and Code Snippets Collection.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4