How do I connect to a MySQL Database in Python?
Connecting to MYSQL with Python 2 in three steps
1 - Setting
You must install a MySQL driver before doing anything. Unlike PHP, Only the SQLite driver is installed by default with Python. The most used package to do so is MySQLdb but it's hard to install it using easy_install. Please note MySQLdb only supports Python 2.
For Windows user, you can get an exe of MySQLdb.
For Linux, this is a casual package (python-mysqldb). (You can use
sudo apt-get install python-mysqldb (for debian based distros),
yum install MySQL-python (for rpm-based), or
dnf install python-mysql (for modern fedora distro) in command line to download.)
For Mac, you can install MySQLdb using Macport.
2 - Usage
After installing, Reboot. This is not mandatory, But it will prevent me from answering 3 or 4 other questions in this post if something goes wrong. So please reboot.
Then it is just like using any other package :
#!/usr/bin/python import MySQLdb db = MySQLdb.connect(host="localhost", # your host, usually localhost user="john", # your username passwd="megajonhy", # your password db="jonhydb") # name of the data base # you must create a Cursor object. It will let # you execute all the queries you need cur = db.cursor() # Use all the SQL you like cur.execute("SELECT * FROM YOUR_TABLE_NAME") # print all the first cell of all the rows for row in cur.fetchall(): print row db.close()
Of course, there are thousand of possibilities and options; this is a very basic example. You will have to look at the documentation. A good starting point.
3 - More advanced usage
I strongly advise you to use it: your life is going to be much easier.
I recently discovered another jewel in the Python world: peewee. It's a very lite ORM, really easy and fast to setup then use. It makes my day for small projects or stand alone apps, Where using big tools like SQLAlchemy or Django is overkill :
import peewee from peewee import * db = MySQLDatabase('jonhydb', user='john', passwd='megajonhy') class Book(peewee.Model): author = peewee.CharField() title = peewee.TextField() class Meta: database = db Book.create_table() book = Book(author="me", title='Peewee is cool') book.save() for book in Book.filter(author="me"): print book.title
This example works out of the box. Nothing other than having peewee (
pip install peewee) is required.
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Here's one way to do it, using MySQLdb, which only supports Python 2:
#!/usr/bin/python import MySQLdb # Connect db = MySQLdb.connect(host="localhost", user="appuser", passwd="", db="onco") cursor = db.cursor() # Execute SQL select statement cursor.execute("SELECT * FROM location") # Commit your changes if writing # In this case, we are only reading data # db.commit() # Get the number of rows in the resultset numrows = cursor.rowcount # Get and display one row at a time for x in range(0, numrows): row = cursor.fetchone() print row, "-->", row # Close the connection db.close()
If you do not need MySQLdb, but would accept any library, I would very, very much recommend MySQL Connector/Python from MySQL: http://dev.mysql.com/downloads/connector/python/.
It is one package (around 110k), pure Python, so it is system independent, and dead simple to install. You just download, double-click, confirm license agreement and go. There is no need for Xcode, MacPorts, compiling, restarting …
Then you connect like:
import mysql.connector cnx = mysql.connector.connect(user='scott', password='tiger', host='127.0.0.1', database='employees') try: cursor = cnx.cursor() cursor.execute(""" select 3 from your_table """) result = cursor.fetchall() print result finally: cnx.close()
Stop Using MySQLDb if you want to avoid installing mysql headers just to access mysql from python.
Use pymysql. It does all of what MySQLDb does, but it was implemented purely in Python with NO External Dependencies. This makes the installation process on all operating systems consistent and easy.
pymysql is a drop in replacement for MySQLDb and IMHO there is no reason to ever use MySQLDb for anything... EVER! -
PTSD from installing MySQLDb on Mac OSX and *Nix systems, but that's just me.
pip install pymysql
That's it... you are ready to play.
Example usage from pymysql Github repo
import pymysql.cursors import pymysql # Connect to the database connection = pymysql.connect(host='localhost', user='user', password='passwd', db='db', charset='utf8mb4', cursorclass=pymysql.cursors.DictCursor) try: with connection.cursor() as cursor: # Create a new record sql = "INSERT INTO `users` (`email`, `password`) VALUES (%s, %s)" cursor.execute(sql, ('[email protected]', 'very-secret')) # connection is not autocommit by default. So you must commit to save # your changes. connection.commit() with connection.cursor() as cursor: # Read a single record sql = "SELECT `id`, `password` FROM `users` WHERE `email`=%s" cursor.execute(sql, ('[email protected]',)) result = cursor.fetchone() print(result) finally: connection.close()
ALSO - Replace MySQLdb in existing code quickly and transparently
If you have existing code that uses MySQLdb, you can easily replace it with pymysql using this simple process:
# import MySQLdb << Remove this line and replace with: import pymysql pymysql.install_as_MySQLdb()
All subsequent references to MySQLdb will use pymysql transparently.
Try using MySQLdb. MySQLdb only supports Python 2.
There is a how to page here: http://www.kitebird.com/articles/pydbapi.html
From the page:
# server_version.py - retrieve and display database server version import MySQLdb conn = MySQLdb.connect (host = "localhost", user = "testuser", passwd = "testpass", db = "test") cursor = conn.cursor () cursor.execute ("SELECT VERSION()") row = cursor.fetchone () print "server version:", row cursor.close () conn.close ()