TestLink

Attempting to connect to mssql, as a result of following line, it returns 'null':
if (!function_exists('mssql_pconnect')) return null;

Any idea/solution?

If you can edit the php.ini file, and this is not a production environment, it is possible to [temporarily] set:

display_errors = On // default is Off

To show the error[s] directly on the page. Make sure to restart the webserver after applying this change.

To the original question: I would say yes for MSSql, but the configuration might be tricky...

Is the mssql extention loaded, or available ? If so, there would be a php_mssql.dll file being loaded in the configuration. Search the php.ini file, it might be there, but may be commented-out with a ;
Of course, that dll should be available within the PHP installation as well.

But know there could be other configuration factors involved. [url, user/pass, etc]

Again, as with any changes to php.ini requires a restart of the webserver.

Thank you very much for the hint. I've turned on the display_error. This is what I get:
Fatal error: Call to undefined function mssql_get_last_message() in C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\testlink\third_party\adodb\drivers\adodb-mssql.inc.php on line 545

I'm trying to connect to TFS (MS Team Foundation Server) database, which is sqlServer.

Ok, but that only covers the first part of my previous post, so that you can see warnings/errors on the page...

What about the other part:

TurboPT wrote: ... I would say yes for MSSql, but the configuration might be tricky...

Is the mssql extention loaded, or available ? If so, there would be a php_mssql.dll file being loaded in the configuration...

Also, if you have the php command-line available, you could also check existence like this:
[the command is the same on Linux] For both, since I don't have mssql configured, I get:

Exception: Function mssql_pconnect() does not exist
Exception: Function mssql_get_last_message() does not exist

It looks like there is no php_mssql.dll but there is php_pdo_sqlsrv_53_nts_vc6.dll. Since the TFS database is sqlServer I've downloaded and installed sqlServer driver from MS (http://msdn.microsoft.com/en-us/sqlserver/ff657782.aspx).
A bunch of php_pdo_sqlsrv_*.dll and php_sqlsrv_*.dll have been installed in PHP\ext directory.

Since my php is 5.3.7, I've added following line in php.ini:
extension=php_pdo_sqlsrv_53_nts_vc6.dll

and this one for mssql:
extension=php_pdo_mssql.dll

I get following errors by running your suggested commands:
C:\php\ext>php --rf mssql_pconnect
PHP Warning: PHP Startup: Unable to load dynamic library 'C:\php\ext\php_pdo_ms
sql.dll' - The specified module could not be found.
in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library 'C:\php\ext\php_pdo_sq
lsrv_53_nts_vc6.dll' - The specified module could not be found.
in Unknown on line 0
Exception: Function mssql_pconnect() does not exist

Since there is no php_pdo_mssql.dll, the first error is obvious, however, I don't know why it can not find php_pdo_sqlsrv_53_nts_vc6.dll.

Since I use MySQL for test link database, I've not installed mssql at the time. I should find out how to add PHP driver for mssql now.

Restart the server after making the extension change?

Taking a brief look through the link you posted, I did find with "system requirement", that is had this:

MS-info-link wrote: Microsoft SQL Server 2008 R2 Native Client is required to use Microsoft Drivers for PHP for SQL Server.

Do know if that is installed? If not, they have a link at the requirements where I found that info.

I had to replace php-5.3.17 with php-5.2.17 and install sql server clien tool.

Cheers,
AO

It's annoying that you had to go back a version [...MicroSoft is supposed to be easier??]

Anyway, whatever it takes to get it working, I guess...