How to connect to PostgreSQL 9 from Drupal 7?

Question

I want to connect to PostgreSQL 9 from Drupal 7.

1. to install drupal files using the following steps.

   wget http://ftp.drupal.org/files/projects/drupal-7.15.tar.gz      
   tar zxvf drupal-7.15.tar.gz    
   sudo mv drupal-7.15/* /var/www/     
   cd /var/www/    
   cp sites/default/default.settings.php
   sites/default/settings.php
   chmod a+w sites/default/settings.php  
   chmod a+w sites/default
   

2. to install PostgreSQL database.

   createuser --pwprompt --encrypted --no-adduser --no-createdb
   username createdb --encoding=UNICODE --owner=username databasename
   

3. to input my_domain in Firefox. It ran across the message:

Maybe it is a problem that Drupal installation program can not access the PostgreSQL database. How to fix it?

Answer 1

The main problem is that you have selected MySQL as your database type. (This is clear from the image you've posted.) Please READ the Installation Guide and act on it. That's what it's there for.

Answer 2

By just reading the title of this question, I thought it was about "How to connect from a Drupal site to some external database in PostGress format". However the details of the question are about "How to use Postgress as the DBMS for hosting the database required for a Drupal site". Consider rephrasing the question title accordingly.

To actually answer this question, consider looking at Install Drupal with PostgreSQL. Here is a quote from that link:

Drupal is an excellent PHP content management system. It supports both MySQL and PostgreSQL as the back end database for content management. Unfortunately, PostgreSQL comes up short in the documentation department: it is not even mentioned in the Drupal INSTALL.txt file. So here we do our small part for the cause and provide some instructions to get Drupal up and running with PostgreSQL.