How to set up a PostgreSQL database in Django

问题:

I'm new to Python and Django.

I'm configuring a Django project using a PostgreSQL database engine backend, But I'm getting errors on each database operation. For example when I run manage.py syncdb, I'm getting:

C:\xampp\htdocs\djangodir>python manage.py syncdb
Traceback (most recent call last):
  File "manage.py", line 11, in <module>
    execute_manager(settings)
  File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line
438, in execute_manager
    utility.execute()
  File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line
379, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line
261, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line
67, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "C:\Python27\lib\site-packages\django\utils\importlib.py", line 35, in im
port_module
    __import__(name)
  File "C:\Python27\lib\site-packages\django\core\management\commands\syncdb.py"
, line 7, in <module>
    from django.core.management.sql import custom_sql_for_model, emit_post_sync_
signal
  File "C:\Python27\lib\site-packages\django\core\management\sql.py", line 6, in
 <module>
    from django.db import models
  File "C:\Python27\lib\site-packages\django\db\__init__.py", line 77, in <modul
e>
    connection = connections[DEFAULT_DB_ALIAS]
  File "C:\Python27\lib\site-packages\django\db\utils.py", line 92, in __getitem
__
    backend = load_backend(db['ENGINE'])
  File "C:\Python27\lib\site-packages\django\db\utils.py", line 33, in load_back
end
    return import_module('.base', backend_name)
  File "C:\Python27\lib\site-packages\django\utils\importlib.py", line 35, in im
port_module
    __import__(name)
  File "C:\Python27\lib\site-packages\django\db\backends\postgresql\base.py", li
ne 23, in <module>
    raise ImproperlyConfigured("Error loading psycopg module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading psycopg module: No mo
dule named psycopg

Can someone give me a clue on what is going on?

回答1:

You need to install psycopg2 Python library.

Installation

---

Download http://initd.org/psycopg/, then install it under Python PATH

After downloading, easily extract the tarball and:

$ python setup.py install

Or if you wish, install it by either easy_install or pip.

^{(I prefer to use pip over easy_install for no reason.)}

• $ easy_install psycopg2
• $ pip install psycopg2

Configuration

---

in settings.py

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'db_name',                      
        'USER': 'db_user',
        'PASSWORD': 'db_user_password',
        'HOST': '',
        'PORT': 'db_port_number',
    }
}

---

^{- Other installation instructions can be found at download page and install page.}

回答2:

Also make sure you have the PostgreSQL development package installed. On Ubuntu you need to do something like this:

$ sudo apt-get install libpq-dev

回答3:

Step by step that I use:

 - sudo apt-get install python-dev
 - sudo apt-get install postgresql-server-dev-9.1
 - sudo apt-get install python-psycopg2 - Or sudo pip install psycopg2

You may want to install a graphic tool to manage your databases, for that you can do:

sudo apt-get install postgresql pgadmin3 

After, you must change Postgre user password, then do:

 - sudo su
 - su postgres -c psql postgres
 - ALTER USER postgres WITH PASSWORD 'YourPassWordHere';
 - \q

On your settings.py file you do:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'dbname',
        'USER': 'postgres',
        'PASSWORD': 'postgres',
        'HOST': '',
        'PORT': '',
    }
}

Extra:

If you want to create the db using the command line you can just do:

- sudo su
- su postgres -c psql postgres
- CREATE DATABASE dbname;
- CREATE USER djangouser WITH ENCRYPTED PASSWORD 'myPasswordHere';
- GRANT ALL PRIVILEGES ON DATABASE dbname TO djangouser;

On your settings.py file you do:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'dbname',
        'USER': 'djangouser',
        'PASSWORD': 'myPasswordHere',
        'HOST': '',
        'PORT': '',
    }
}

回答4:

This may seem a bit lengthy, but it worked for me without any error.

At first, Install phppgadmin from Ubuntu Software Center.

Then run these steps in terminal.

sudo apt-get install libpq-dev python-dev
pip install psycopg2
sudo apt-get install postgresql postgresql-contrib phppgadmin

Start the apache server

sudo service apache2 start

Now run this too in terminal, to edit the apache file.

sudo gedit /etc/apache2/apache2.conf

Add the following line to the opened file:

Include /etc/apache2/conf.d/phppgadmin

Now reload apache. Use terminal.

sudo /etc/init.d/apache2 reload

Now you will have to create a new database. Login as 'postgres' user. Continue in terminal.

sudo su - postgres

In case you have trouble with the password of 'postgres', you can change it using the answer here https://stackoverflow.com/a/12721020/1990793 and continue with the steps.

Now create a database

createdb <db_name>

Now create a new user to login to phppgadmin later, providing a new password.

createuser -P <new_user>

Now your postgressql has been setup, and you can go to:

http://localhost/phppgadmin/

and login using the new user you've created, in order to view the database.

回答5:

You can install "psycopg" with the following command:

# sudo easy_install psycopg2

Alternatively, you can use pip :

# pip install psycopg2

easy_install and pip are included with ActivePython, or manually installed from the respective project sites.

Or, simply get the pre-built Windows installer.

回答6:

The immediate problem seems to be that you're missing the psycopg module.

回答7:

If you are using Fedora 20, Django 1.6.5, postgresql 9.3.* and you need the psycopg2 module, do this:

yum install postgresql-devel
easy_install psycopg2

If you are like me, you may have trouble finding the well documented libpq-dev rpm... The above worked for me just now.

回答8:

I was having the same Issue on Mac.

The solution was to use only PIP to install everything, and touch some things.

First install PIP from: https://pip.pypa.io/en/latest/

Then you want to make sure if path to pg_config is in your PATH (echo $PATH), if not you can edit your bash_profile:

vi /Users/<user>/.bash_profile

and add this line:

export PATH=$PATH:/path/to/pg_config/bin

If you don't know where pg_config is you can use the "locate" tool, but be sure your locate.db is up to date (i was using an old locate.db and using paths that does not exists).

sudo /usr/libexec/locate.updatedb
locate pg_config

Then install Django (if needed) and psycopg2.

sudo pip install Django
sudo pip install psycopg2

And then in settings.py (localhost:defaultport)

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'dbname',
        'USER': 'postgres',
        'PASSWORD': 'postgres',
        'HOST': '',
        'PORT': '',
    }
}

Greets!

回答9:

$ sudo apt-get install libpq-dev

Year, this solve my problem. After execute this, do: pip install psycopg2

回答10:

Please note that installation of psycopg2 via pip or setup.py requires to have Visual Studio 2008 (more precisely executable file vcvarsall.bat). If you don't have admin rights to install it or set the appropriate PATH variable on Windows, you can download already compiled library from here.

回答11:

This is one of the very good and step by step process to set up PostgreSQL in ubuntu server. I have tried it with Ubuntu 16.04 and its working.

https://www.digitalocean.com/community/tutorials/how-to-use-postgresql-with-your-django-application-on-ubuntu-14-04