How do I connect to a MySQL Database in Python?

Question

How do I connect to a MySQL database using a python program?

Answer 1

Run this command in your terminal to install mysql connector:

pip install mysql-connector-python

And run this in your python editor to connect to MySQL:

import mysql.connector

mydb = mysql.connector.connect(
      host="localhost",
      user="yusername",
      passwd="password",
      database="database_name"
)

Samples to execute MySQL Commands (in your python edior):

mycursor = mydb.cursor()
mycursor.execute("CREATE TABLE customers (name VARCHAR(255), address VARCHAR(255))")    
mycursor.execute("SHOW TABLES")

mycursor.execute("INSERT INTO customers (name, address) VALUES ('John', 'Highway 21')")    
mydb.commit() # Use this command after insert or update

For more commands: https://www.w3schools.com/python/python_mysql_getstarted.asp

Answer 2

MySQLdb is the straightforward way. You get to execute SQL queries over a connection. Period.

My preferred way, which is also pythonic, is to use the mighty SQLAlchemy instead. Here is a query related tutorial, and here is a tutorial on ORM capabilities of SQLALchemy.

Answer 3

Even though some of you may mark this as a duplicate and get upset that I am copying someone else's answer, I would REALLY like to highlight an aspect of Mr. Napik's response. Because I missed this, I caused nationwide website downtime (9min). If only someone shared this information, I could have prevented it!

Here is his code:

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()

The important thing here is the Try and Finally clause. This allows connections to ALWAYS be closed, regardless of what happens in the cursor/sqlstatement portion of the code. A lot of active connections cause DBLoadNoCPU to spike and could crash a db server.

I hope this warning helps to save servers and ultimately jobs! :D

Answer 4

SqlAlchemy

---

SQLAlchemy is the Python SQL toolkit and Object Relational Mapper that gives application developers the full power and flexibility of SQL. SQLAlchemy provides a full suite of well known enterprise-level persistence patterns, designed for efficient and high-performing database access, adapted into a simple and Pythonic domain language.

Installation

pip install sqlalchemy

RAW query

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, scoped_session

engine = create_engine("mysql://<user_name>:<password>@<host_name>/<db_name>")
session_obj = sessionmaker(bind=engine)
session = scoped_session(session_obj)

# insert into database
session.execute("insert into person values(2, 'random_name')")
session.flush()
session.commit()

ORM way

from sqlalchemy import Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, scoped_session

Base = declarative_base()
engine = create_engine("mysql://<user_name>:<password>@<host_name>/<db_name>")
session_obj = sessionmaker(bind=engine)
session = scoped_session(session_obj)

# Bind the engine to the metadata of the Base class so that the
# declaratives can be accessed through a DBSession instance
Base.metadata.bind = engine

class Person(Base):
    __tablename__ = 'person'
    # Here we define columns for the table person
    # Notice that each column is also a normal Python instance attribute.
    id = Column(Integer, primary_key=True)
    name = Column(String(250), nullable=False)

# insert into database
person_obj = Person(id=12, name="name")
session.add(person_obj)
session.flush()
session.commit()

Answer 5

PyMySQL 0.10.1 - Released: Sep 10, 2020, has support for python3 as well.

python3 -m pip install PyMySQL

Simple code:

import pymysql

# Connect to the database
conn = pymysql.connect(host='127.0.0.1',user='root',passwd='root',db='fax')

# Create a Cursor object
cur = conn.cursor()

# Execute the query
cur.execute("SELECT * FROM fax.student")

# Read and print records
for row in cur.fetchall():
    print(row)

output:

(1, 'Petar', 'Petrovic', 1813, 'Njegusi')
(2, 'Donald', 'Tramp', 1946, 'New York')
(3, 'Bill', 'Gates', 1955, 'Seattle')

Answer 6

Also take a look at Storm. It is a simple SQL mapping tool which allows you to easily edit and create SQL entries without writing the queries.

Here is a simple example:

from storm.locals import *

# User will be the mapped object; you have to create the table before mapping it
class User(object):
        __storm_table__ = "user" # table name
        ID = Int(primary=True) #field ID
        name= Unicode() # field name

database = create_database("mysql://root:password@localhost:3306/databaseName")
store = Store(database)

user = User()
user.name = u"Mark"

print str(user.ID) # None

store.add(user)  
store.flush() # ID is AUTO_INCREMENT

print str(user.ID) # 1 (ID)

store.commit() # commit all changes to the database

To find and object use:

michael = store.find(User, User.name == u"Michael").one()
print str(user.ID) # 10

Find with primary key:

print store.get(User, 1).name #Mark

For further information see the tutorial.