FreeTDS™ consists of some C libraries.
The FreeTDS™ libraries support three separate APIs: DB-Library, CT-Library, and ODBC.
Underlying these three is libtds, which handles the low-level details of the TDS protocol,
such as sending, receiving, and datatype conversion.
This document and the FreeTDS website are dedicated to these libraries.
The libraries are portable, mature, and stable. They're expected to compile readily and normally do not crash or corrupt data. Extensive logging aids in diagnosing problems. While they do not include every feature provided by the vendors' libraries, they do faithfully implement a useful — and widely used — subset of their APIs.
The DB-Library and CT-Library APIs have been usable for several years. They have been successfully substituted for Sybase's own libraries in a variety of venues, including Perl™ and PHP™.
The ODBC driver should be fully ODBC 3.5 compliant.
Basic API coverage information for all libraries may be found in this manual. It is maintained in doc/api_status.txt, included in the source distribution.
![[Note]](../images/note.gif) | Note |
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For Microsoft servers, FreeTDS™ now offers the best |
In addition to the core DB-Library API, FreeTDS™ includes a full implementation of DB-Library's bcp functions, as well as freebcp, a replacement for Sybase's bcp utility.
How big is it? FreeTDS™ has over 100,000 lines of C code, maintained by a handful of developers. Patches arrive irregularly, varying in size from one-liners to thousand-line monsters. Almost all are applied or used in some way. The mailing list has some 600 or so subscribers at this writing. Safe to say, FreeTDS™'s success so far lies somewhere between the Beetle and the Edsel.
Who uses it? Oh, pretty much everyone. FreeTDS™ users number in the tens of thousands. It's used by large corporations, by the U.S. federal government (e.g. Database Access Library at the National Center for Biotechnology Information) and, judging by the mailing list, by many webservers running Apache and PHP. Sybase recommends FreeTDS™ for their EAServer product. Microsoft recommends FreeTDS™ to their customers who want access to Microsoft SQL Server from non-Win32 clients. So do we.
You may be wondering how these libraries fit with Perl, PHP, TCL, Python, or other popular scripting languages. Most of these languages have bindings to Sybase that use either the DB-Library or CT-Library API, for which FreeTDS™ is intended as a drop-in replacement. For instance, Michael Peppler's DBD::Sybase works very well using FreeTDS™ to access Sybase or Microsoft SQL Server™s. PHP™ has options for sybase (DB-Library) and sybase-ct (CT-Library) APIs.
Should FreeTDS™ not suit your needs, some alternatives
- jTDS
If Java is your game, we refer you to the jTDS project on SourceForge. It is a fork of the FreeTDS/JDBC™ project, by Craig Spannring, and is a free, native 100% Java implementation of a Type 4 JDBC driver.
- Sybase OpenClient
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In the time since FreeTDS™ was started, Sybase (as well as most major DBMS vendors) has released its database for the Intel GNU/Linux™ platform. The good: it is a solid product and supports TDS 4.2 and TDS 5.0. The bad: it doesn't support TDS 7.0 or Linux/*BSD on non-Intel platforms. The ugly: Microsoft broke date handling for big endian Sybase clients.
Depending on platform, it may cost something.
ODBCbridge productsThey use the
ODBCdriver on the NT box where your SQL Server™ runs so you'll never have trouble with new protocols and the like. On the downside, they can be costly and may be inefficient. We know of EasySoft ODBC-ODBC Bridge™ from EasySoft, Universal Data Access Driver™ from OpenLink Software, andODBCRouter from August Software Corporation.- DBD::Proxy
We have no direct experience with this Perl-only option. It has the same caveats as an
ODBCbridge except it's free.
[3] Microsoft ceased enhancing DB-Library in 2001, advising customers to “avoid using DB-Library”. For Microsoft's unmaintained product, that's good advice. But if the DB-Library specification meets your needs, FreeTDS™ permits you to keep using it with little loss (and some gain) of functionality.