DataDirect Technologies developed and continues to
maintain the Microsoft JDBC Driver for SQL Server. It was
not reverse engineered. Microsoft and DataDirect
Technologies have a long term business relationship that
includes porting the SQL Server ODBC driver to non-Windows
platforms as well as the work on the JDBC driver.
>-----Original Message-----
>Writing something like an ODBC driver for SQL Server
involves two sides: the
>ODBC specification itself (which applies to all data
sources) and SQL Server
>access. For the ODBC and OLE DB specifications, see
>http://msdn.microsoft.com/library/en-
us/mdacsdk/htm/mdacstartpage1.asp. For
>the JDBC specification, see
http://java.sun.com/products/jdbc/.
>
>The SQL Server side is a bit tougher, because Microsoft
does not document
>everything you would need to know to write a fully
functional,
>high-performance driver which talks directly to a client
Net-Library or
>communicates across the wire using TDS. Luckily, there
are no applications
>which use every single little feature of SQL Server, so
most third-party
>drivers can get away with implementing a subset of
functionality. Some
>drivers have bigger/smaller subsets than others and
perform better/worse
>than others because their authors are more/less
successful at
>reverse-engineering what Microsoft does not document.
Microsoft's JDBC
>driver was written by DataDirect Technologies, so it was
originally based on
>reverse-engineering, too. Even though Microsoft is now
maintaining the code
>and can shore up the SQL Server side of the JDBC driver,
the JDBC
>specification (controlled by Sun) is not as well matched
to SQL Server as
>Microsoft's own ODBC, OLE DB, and .NET Data Provider
specifications.
>
>As long as you're just wanted to get an understanding of
the basics, there
>is some informal/incomplete/outdated material you can
look at. If you search
>Books Online for "Tabular Data Stream" you will find a
few references to
>TDS, located in topics which will give you a little idea
of what you're
>getting into.
>
>You can download Sybase's documentation for their current
flavor of TDS from
>http://crm.sybase.com/sybase/www/ESD...c_download.jsp
.. Microsoft's
>current flavor of TDS has differences, primarily in areas
like Unicode and
>data types which were added after Microsoft's split from
Sybase in 1994, but
>Microsoft's TDS 8.0 still looks conceptually a lot like
Sybase TDS 4.2.
>Since Microsoft does not provide any TDS 8.0
documentation similar in detail
>to Sybase's TDS 5.0 documentation, Sybase's document is
as close as you can
>come to finding anything formal.
>
>For sample source code, you can check out the various
open source efforts at
>creating a DB-Lib equivalent, ODBC driver, JDBC driver,
and .NET Data
>Provider for SQL Server:
>http://www.freetds.org/userguide/
>http://jtds.sourceforge.net/
>http://www.go-mono.com/sqlclient.html
>
>
>"Henry Stock" <hstock@onproject.com> wrote in message
>news:O7ZqPhxGDHA.3692@tk2msftngp13.phx.gbl...
>> issue. But it has made me interested in what it takes
to build an
>interface
>> driver such as an ODBC or a JDBC driver. I do not
claim to be an expert
>> programmer, but I want to learn what I can about the
process. I want to
>> find information on the SQL Server API's that drivers
access, how they are
>> accessed, and perhaps find examples of code of a sample
driver. I have an
>
>
>.
>