如何在 Django 中设置 PostgreSQL 数据库

Question

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?

Answer 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 .}

Answer 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

Answer 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 pgadmin4 

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': '',
    }
}

Answer 4

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 .

Answer 5

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.

Answer 6

直接的问题似乎是您缺少psycopg2模块。

Answer 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.

Answer 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!

Answer 9

$ sudo apt-get install libpq-dev

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

Answer 10

Steps to create a Django app with PostgreSQL database from scratch.

1. Check if PostgreSQL is installed in your system. In your bash shell enter

   psql --version

2. If PostgreSQL is installed jump to step 6.

3. To install PostgreSQL -

    sudo apt-get install python3-dev libpq-dev sudo apt-get install postgresql postgresql-contrib

4. By default PostgreSQL installation creates a special user named "postgres" that has all rights. To login to PostgreSQL

    sudo -u postgres psql

   To exit PostgreSQL session

   \q

5. Now set password for "postgres" user.

   Login to PostgreSQL -

    sudo -u postgres psql

   In PostgreSQL interactive session enter -

    \password postgres

6. Create PostgreSQL database.

   To create directly from bash shell -

    sudo -u postgres createdb your_db_name

   To create from PostgreSQL interactive session -

    createdb your_db_name

   To check if the database is created, list all databases using PostgreSQL command

   \l

7. If you already have an existing Django project then jump to step 11. Otherwise create a virtual environment. I use virtualenv wrapper.

    mkvirtualenv your_project_name

8. Create Django project.

    django-admin startproject your_project_name

9. Cd to the project directory and create your app.

    python manage.py startapp your_app_name

10. Install Django.

     pip install django

11. Install Psycopg2. Psycopg2 is a PostgreSQL database adapter for Python. This is required for Django to connect with PostgreSQL.

     pip install psycopg2

12. Update settings.py as follows

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

13. Run migration.

     python3 manage.py migrate

14. Run Django server and visit localhost:8000

     python3 manage.py runserver 0.0.0.0:8000

15. If required you can install pgadmin - a graphical client to view and manipulate PostgreSQL database schema and data.

Answer 11

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 .

Answer 12

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

Answer 13

integrating postgresql in django

Arch: Ubuntu and Nginx

sudo apt install libpq-dev postgresql postgresql-contrib

systemctl status postgresql.service is usually active by now if not check back installation

By default, Postgres uses an authentication scheme called “ peer authentication ” for local connections. Basically, this means that if the user's operating system username john@example matches a valid Postgres username john , that user can login with no further authentication. During the Postgres installation, an operating system user named postgres was created to correspond to the postgres administrative user. We use this user to perform administrative tasks.

sudo -u postgres psql

postgres=# create database example;
CREATE DATABASE
postgres=# create user john with password 'abcxyz';
CREATE ROLE
postgres=# ALTER ROLE john SET client_encoding TO 'utf8';
postgres=# ALTER ROLE john SET default_transaction_isolation TO 'read committed';
postgres=# ALTER ROLE john SET timezone TO 'UTC';
postgres=# GRANT ALL PRIVILEGES ON DATABASE example TO john;

Postgres is now set up so that Django can connect to and manage its database information.

pip install psycopg2-binary is not recommended for production as psycopg2 has unfixed issues.

settings.py

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'example',
        'USER': 'john',
        'PASSWORD': 'abcxyz',
        'HOST': 'localhost',
        'PORT': '5432',  can be left empty
    }
}

At the end, use these basic django migration commands to complete the integration.

python manage.py makemigrations

python manage.py migrate

Extra TODO Tips

It is highly recommended to use better methods to set critical values like NAME, USER and PASSWORD rather than using plain text like shown above in database code snippet.

One method could be using a json file to replace those contents from outside the scope of project root directories. So even in unforeseeable cases of attempted source code hijacking your critical auth details could be out of reach.

A new config.json file with corresponding key-value pairs is assumed to be created.

{
  "POSTGRES_DB": "example",
  "POSTGRES_USER": "john",
  "POSTGRES_PASSWORD": "abcxyz",
  "POSTGRES_HOST": "localhost",
  "POSTGRES_PORT": ""
}

Placing this code in settings.py to load and use config.json .

import os
import json

with open('/path to your config.json file/') as config_file:
    config = json.load(config_file)

Update database config to load the params from config.json file:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': config['POSTGRES_DB'],
        'USER': config['POSTGRES_USER'],
        'PASSWORD': config['POSTGRES_PASSWORD'],
        'HOST': config['POSTGRES_HOST'],
        'PORT': config['POSTGRES_PORT'],
    }
}

Answer 14

postgres 14 在端口 5433 上运行在 settings.py 中指定