Using MySQL

To start using MySQL, you'll need to go to the MySQL tab on your dashboard, and set up a password. You'll also find the connection settings (host name, username) on that tab, as well as the ability to create new databases.

You can start a new MySQL console to access your databases from this tab too, or alternatively you can open a MySQL shell with the following command from a bash console or ssh session:

mysql -u USERNAME -h HOSTNAME -p 'USERNAME$DATABASENAME'

In this:

• The USERNAME is the username you use to log in to PythonAnywhere
• The HOSTNAME is on your Databases tab
• The 'USERNAME$DATABASENAME' is the full name of your database, which comprises your username, then a dollar sign, then the name you gave it. The single quotes around it are important! If you don't put them in there, bash will try to interpret the $DATABASENAME as an environment variable, which will lead to an error saying ERROR 1044 (42000): Access denied for user 'USERNAME'@'%' to database 'USERNAME'

When you run the command, it will prompt you for a password -- use the one you entered on the Databases tab.

Accessing MySQL from Python¶

The appropriate libraries are installed for all versions of Python that we support, so if you're not using a virtualenv, to access a MySQL database just import MySQLdb.

If you are using a virtualenv, you'll need to install the correct package yourself. Start a bash console inside the virtualenv, then:

For Python 2.7

pip install mysqlclient==1.4.6

For Python 3.x

pip install mysqlclient

MySQL with Django¶

To configure Django to access a MySQL database on PythonAnywhere, you need to do this in your settings file:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': '<your_username>$<your_database_name>',
        'USER': '<your_username>',
        'PASSWORD': '<your_mysql_password>',
        'HOST': '<your_mysql_hostname>',
    }
}

Again, you can get the username and hostname details from the "Databases" tab.

MySQL with Django tests¶

When you run Django tests that use the database, Django tries to create a database called test_<original database name> and that will fail because Django does not have permissions to create a new database. To run Django tests on PythonAnywhere, add a TEST key to your database definition in settings.py. Like this:

DATABASES = {
    'default': {
         ...
        'TEST': {
          'NAME': '<your username>$test_<your database name>',

More info here: https://docs.djangoproject.com/en/3.2/ref/settings/#test

We suggest you use a form like <your username>$test_<your database name>. Create this database from the PythonAnywhere Databases tab and Django will happily use it and run your tests.

MySQL with Flask¶

We strongly recommend that you use the Flask-SQLAlchemy module for this. Check out this help page for more details.

MySQL with web2py¶

To use MySQL with web2py, you'll need to change your DAL constructor:

db = DAL('mysql://<your_username>:<your_mysql_password>@<your_mysql_hostname>/<your_database_name>')

Handling connection timeout errors¶

If you're seeing unexpected 'disconnected' errors, it may be due to our connection timeouts. We set a 5-minute timeout on idle database connections, so you'll want to handle unexpected disconnects, either manually with some sort of try/except, or, if you're using an ORM, by setting a timeout on the longevity of workers in your connection pool. SQLAlchemy has a pool_recycle argument, for example: https://docs.sqlalchemy.org/en/latest/core/pooling.html?#setting-pool-recycle

Backup and restore¶

See this article on mysqldump.

Checking MySQL database size¶

See this help page.

Deleting existing database¶

Start a MySQL console and run the following command:

drop database `<your_username>$<your_database_name>`;

replacing placeholders in brackets respectively with your username and the database name that should be deleted.

Character sets, UTF-8, internationalization, etc¶

See this article on character sets.

Caveat: you don't have system administration privileges on PythonAnywhere¶

If you see an error containing the message like this:

1227, 'Access denied; you need (at least one of) the SYSTEM_VARIABLES_ADMIN or SESSION_VARIABLES_ADMIN privileges

it probably means that you try to use some settings that require system variable privileges which PythonAnywhere users don't have.

For example, if you use Django framework, such settings could look like:

DATABASES = {
    ...
    "OPTIONS": {
        "init_command": "SET innodb_strict_mode=1",
    },
    ...
}