I got this error during installation.

Fatal error: Unable to connect to database in /var/www/html/class/database/databasefactory.php on line 34

I am using RedHat 9, all require package are installed.

I can access the database as root.

mysql> status
--------------
mysql Ver 11.18 Distrib 3.23.54, for redhat-linux-gnu (i386)

Connection id: 32
Current database: wkportal
Current user: root@localhost
Current pager: stdout
Using outfile: ''
Server version: 3.23.54
Protocol version: 10
Connection: Localhost via UNIX socket
Client characterset: latin1
Server characterset: latin1
UNIX socket: /var/lib/mysql/mysql.sock
Uptime: 29 min 55 sec

Threads: 2 Questions: 42 Slow queries: 0 Opens: 8 Flush tables: 1 Open tables: 2 Queries per second avg: 0.023
--------------

mysql> quit

I assume you're using the same root user/password combination in XOOPS setup. Do you have the server set to 'localhost' or whatever it should be? Double-check the spelling of everything. Whch version of XOOPS are you running? One early version of 2.0.4 (I think it has been repackaged now) had a small problem in the installer which gave this error.

I would also recommend creating a MySQL user for XOOPS instead of using 'root'. That way you can give access just to the XOOPS database and not all databases running on your server.