How do I connect to a MySQL database using a python program?
First install the driver (Ubuntu)
sudo apt-get install python-pip
sudo pip install -U pip
sudo apt-get install python-dev libmysqlclient-dev
sudo apt-get install MySQL-python
MySQL database connection codes
import MySQLdb
conn = MySQLdb.connect (host = "localhost",user = "root",passwd = "pass",db = "dbname")
cursor = conn.cursor ()
cursor.execute ("SELECT VERSION()")
row = cursor.fetchone ()
print "server version:", row[0]
cursor.close ()
conn.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()
This is Mysql DB connection
from flask import Flask, render_template, request
from flask_mysqldb import MySQL
app = Flask(__name__)
app.config['MYSQL_HOST'] = 'localhost'
app.config['MYSQL_USER'] = 'root'
app.config['MYSQL_PASSWORD'] = 'root'
app.config['MYSQL_DB'] = 'MyDB'
mysql = MySQL(app)
@app.route('/', methods=['GET', 'POST'])
def index():
if request.method == "POST":
details = request.form
cur = mysql.connection.cursor()
cur.execute ("_Your query_")
mysql.connection.commit()
cur.close()
return 'success'
return render_template('index.html')
if __name__ == '__main__':
app.run()
First step to get The Library:
Open terminal and execute pip install mysql-python-connector
.
After the installation go the second step.
Second Step to import the library:
Open your python file and write the following code:
import mysql.connector
Third step to connect to the server: Write the following code:
conn = mysql.connector.connect(host=
you host name like localhost or 127.0.0.1
, username=your username like root
, password =your password
)
Third step Making the cursor:
Making a cursor makes it easy for us to run queries.
To make the cursor use the following code:
cursor = conn.cursor()
Executing queries:
For executing queries you can do the following:
cursor.execute(query)
If the query changes any thing in the table you need to add the following code after the execution of the query:
conn.commit()
Getting values from a query:
If you want to get values from a query then you can do the following:
cursor.excecute('SELECT * FROM
table_name') for i in cursor: print(i) #Or for i in cursor.fetchall(): print(i)
The fetchall() method returns a list with many tuples that contain the values that you requested ,row after row .
Closing the connection:
To close the connection you should use the following code:
conn.close()
Handling exception:
To Handel exception you can do it Vai the following method:
try: #Logic pass except mysql.connector.errors.Error: #Logic pass
To use a database:
For example you are a account creating system where you are storing the data in a database named blabla, you can just add a database parameter to the connect() method ,like
mysql.connector.connect(database =
database name)
don't remove other informations like host,username,password.
Oracle (MySQL) now supports a pure Python connector. That means no binaries to install: it's just a Python library. It's called "Connector/Python".
http://dev.mysql.com/downloads/connector/python/
for Python3.6 I found two driver: pymysql and mysqlclient. I tested the performance between them and got the result: the mysqlclient is faster.
below is my test process(need install python lib profilehooks to analyze time elapse:
raw sql: select * from FOO;
immediatly execute in mysql terminal:
46410 rows in set (0.10 sec)
pymysql (2.4s):
from profilehooks import profile
import pymysql.cursors
import pymysql
connection = pymysql.connect(host='localhost', user='root', db='foo')
c = connection.cursor()
@profile(immediate=True)
def read_by_pymysql():
c.execute("select * from FOO;")
res = c.fetchall()
read_by_pymysql()
here's the pymysql profile:
mysqlclient (0.4s)
from profilehooks import profile
import MySQLdb
connection = MySQLdb.connect(host='localhost', user='root', db='foo')
c = connection.cursor()
@profile(immediate=True)
def read_by_mysqlclient():
c.execute("select * from FOO;")
res = c.fetchall()
read_by_mysqlclient()
here's the mysqlclient profile:
So, it seems that mysqlclient is much faster than pymysql