Using MySQL in Flask

Question

Can someone share example codes in Flask on how to access a MySQL DB? There have been documents showing how to connect to sqlite but not on MySQL.

Thank you very much in advance

Solution 1

Firstly you need to install Flask-MySQL package. Using pip for example:

pip install flask-mysql

Next you need to add some configuration and initialize MySQL:

from flask import Flask
from flaskext.mysql import MySQL

app = Flask(__name__)
mysql = MySQL()
app.config['MYSQL_DATABASE_USER'] = 'root'
app.config['MYSQL_DATABASE_PASSWORD'] = 'root'
app.config['MYSQL_DATABASE_DB'] = 'EmpData'
app.config['MYSQL_DATABASE_HOST'] = 'localhost'
mysql.init_app(app)

Now you can get connection and cursor objects and execute raw queries:

conn = mysql.connect()
cursor =conn.cursor()

cursor.execute("SELECT * from User")
data = cursor.fetchone()

Solution 2

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://username:password@server/db'
db = SQLAlchemy(app)


class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(120), unique=True)

    def __init__(self, username, email):
        self.username = username
        self.email = email

    def __repr__(self):
        return '<User %r>' % self.username

help link

Solution 3

Pretty simple with pymysql:

from flask import Flask, request, render_template
import pymysql

db = pymysql.connect("localhost", "username", "password", "database")

app = Flask(__name__)
api = Api(app)

@app.route('/')
def someName():
    cursor = db.cursor()
    sql = "SELECT * FROM table"
    cursor.execute(sql)
    results = cursor.fetchall()
    return render_template('index.html', results=results)

if __name__ == '__main__':
app.run(debug=True)

In your index.html file just do something like:

<div>
<% for row in results %}
      <tr>
         <td>{{ row[0] }}</td>
         <td>{{ row[1] }}</td>
         <td>{{ row[2] }}</td>
         <td>{{ row[3] }}</td>
      </tr>
{% endfor %}
</div>

Solution 4

Easy with Mysql,

1. Create db with following command

   CREATE TABLE MyUsers ( firstname VARCHAR(30) NOT NULL,  lastname VARCHAR(30) NOT NULL);
   

2. Copy paste below code in app.py file

   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
           firstName = details['fname']
           lastName = details['lname']
           cur = mysql.connection.cursor()
           cur.execute("INSERT INTO MyUsers(firstName, lastName) VALUES (%s, %s)", (firstName, lastName))
           mysql.connection.commit()
           cur.close()
           return 'success'
       return render_template('index.html')
   
   
   if __name__ == '__main__':
          app.run()
   

Solution 5

#!/usr/bin/python
from flask import Flask,jsonify,abort, make_response
import MySQLdb

app = Flask(__name__)

db = MySQLdb.connect("localhost", "root", "yourDbPassWord", "DBname")

@app.route('/api/v1.0/items', methods=['GET'])
def get_items():
    curs = db.cursor()
    try:
        curs.execute("SELECT * FROM items")
        ...

    except:
        print "Error: unable to fetch items"
    return jsonify({"desired: " response})

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Comments

[Ken Kinder]

yes but that's with sqlalchemy. what about just straight mysql?

[JAL]

Thanks for your answer. Rather than just posting code, can you provide a little bit more about what this code does?

[ridderhoff]

Could be wrong, but pretty sure there are issues with using pymysql in a multi-threaded environment. Gave me random errors last time I tried this.

[ZF007]

As this is an older question: post mysql version to which your answer applies.

[Sam]

I am having this error: ImportError: No module named 'flask_mysqldb'

[Amanur Rahman]

@Sanya You need to install "flask-mysqldb" module by pip. The command is "pip install flask-mysqldb" without quota mark.