Drop support for pdo_dblib on Windows

[cmb69]

Description

I just had a closer look at https://github.com/php/php-src/blob/master/ext/pdo_dblib/config.w32, and found it amazing that you can build the same DLL with two different names by just configuring --with-pdo-dblib and --with-pdo-mssql, if you manage to get the appropriate dependencies. That appears to be a problem, though, since FreeTDS claims to be a set of libraries for Unix and Linux, and to my knowlegde Sybase and Microsoft SQL Server are no longer compatible for decades. Furthermore, it occurs to me that pdo_sqlsrv is preferred to work with MS SQL Server for many years, and I can hardly imagine that anybody still uses pdo_mssql to connect to an SAP ASE (what it's apparently called since 2010).

For what it's worth, the official Windows builds neither contain php_pdo_dblib.dll nor php_pdo_mssql.dll for a long time.

So, can anyone shed some light on the state of pdo_dblib on Windows? Does anybody still use it? Can it even be built?

If not, I suggest to drop support for pdo_dblib on Windows altogether (i.e. remove config.w32 and the couple of Windows specific code in the C sources of the extension). And yes, this requires discussion on the internals and internals-win mailing lists, and possibly an RFC, but I wanted to gauge the feedback on this ticket first.

/cc @SakiTakamachi as codeowner of pdo_dblib

[SakiTakamachi]

@cmb69

It's pretty rare to see people connecting to Sybase using dblib, but that's what I've seen at least this year.

#13475

However, for SqlServer there is pdo_sqlsrv as you mentioned, and even if not odbc tends to be preferred.

I've never built this on windows so I don't know about that.

I'll check once to see what the difference is between building it as mssql and building it as dblib.

[cmb69]

It's pretty rare to see people connecting to Sybase using dblib, but that's what I've seen at least this year.

Yeah, I suppose that pdo_dblib works on Linux/Unix systems using FreeTDS. The question is if pdo_dblib/pdo_mssql is still supported on Windows. I would download that "free" trial, if it was free.

[SakiTakamachi]

I've looked into it a bit, but I haven't found any useful information yet...

[cmb69]

@Jan-E, did you ever try to build pdo_dblib on Windows (either using --with-pdo-dblib or --with-pdo-mssql)?

[Jan-E]

There is only one php_dblib.dll on my laptop, for a X64 (!) PHP 5.3.8. And one php_pdo_dblib.dll for a X64 PHP 5.3.28, which is dependent on libsybdb64.dll (Sybase). So it is fairly safe to drop support for pdo_dblib. on Windows.

[cmb69]

Thank, @Jan-E! That helped me to find https://php-legacy-docs.zend.com/manual/php5/en/ref.pdo-dblib:

If it is not possible to use SqlSrv, you can use the PDO_ODBC driver to connect to Microsoft SQL Server and Sybase databases, as the native Windows DB-LIB is ancient, thread un-safe and no longer supported by Microsoft.

So, indeed, dropping support for pdo_dblib on Windows (and only on Windows) appears to be sensible.

PS: hah, it's still in "our" docs: https://www.php.net/pdo_dblib

[cmb69]

I've written to the mailing list: https://news-web.php.net/php.internals/124777 (but forgot to actually include the Windows internals mailing list; maybe not an issue).

[SakiTakamachi]

I've looked into it for a while now and I think it's okay to drop it.

[cmb69]

I've looked into it for a while now and I think it's okay to drop it.

Thanks! I agree, also considering that there has been no feedback on https://news-web.php.net/php.internals/124777. However, I don't consider this urgent, and since we're already late in the PHP 8.4 QA release cycle, I suggest to postpone this to PHP next (i.e. 8.5 or 9.0).