when python use DB mysql

https://stackoverflow.com/questions/372885/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[0] 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

Once you know how it works, You may want to use an ORM to avoid writing SQL manually and manipulate your tables as they were Python objects. The most famous ORM in the Python community is SQLAlchemy.

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.