Since I develop on localhost but deploy elsewhere, and since I don't want to have to force my sites to be under a Windows partition's root directory (currently F:\web_dev\htdocs), code like this:
require_once($_SERVER['DOCUMENT_ROOT'] . '/projXY/database/database_common.php');
OdbcExec($sql); // defined in the file above
causes Netbeans to issue a "Warning: unknown function".
Now, I could get round this by using a directory structure like :
F:\project_1
F:\project_2
instead of
F:\web_dev_htdocs\project_1
F:\web_dev_htdocs\project_2
and then using
require_once('/database/database_common.php');
BUT that imposes constraints on where the end-user an install my site.
Simplest by far would be to tell NetBeans which local directory corresponds to $_SERVER['DOCUMENT_ROOT'], but I can't find a configuration option for that. I am sure this is a common problem. Any suggestions?
Update: NetbBeans v7.0.1
Simply add the /path/to/projXY/database/ directory to your project's include path. Netbeans will then pick up the files there and use them as code references.
http://netbeans.org/kb/docs/php/project-setup.html#phpIncludePath
Relying on $_SERVER['DOCUMENT_ROOT'] is generally a bad idea. For one, it eliminates the ability to run parts of your application via the console / command line.
You should instead either use configurable, absolute paths to shared libraries or do as in Brandon's answer and use a relative path from __DIR__ (PHP 5.3) or dirname(__FILE__)
Not sure if this is what you are looking for or not, but I commonly use:
require_once(dirname(__FILE__) . DIRECTORY_SEPARATOR . 'file.php');