Hi Tushar

> ODBC is one of the very few open technology initiated by Microsoft
> http://en.wikipedia.org/wiki/ODBC says
> Microsoft created ODBC by adapting the SQL Access Group CLI. It released ODBC 1.0 in September, 1992.
>
> Since ODBC is an open standard, Microsoft does not have full control over it.

Sorry, you are correct and I should have been more specific. Microsoft took the SAG work at the end of the eighties and used it to propose a standard back to the SAG....I should have said that they did not "invent" it. This is from the ODBC standards definition:

For several years, a working party called the SQL-Access Group (SAG), consisting of interested hardware and software vendors , worked towards defining a common database access method to simplify Client-Server computing. Microsoft has taken a core set of SAG's output and developed a call-level interface called the Open Database Connectivity (ODBC) Application Programming Interface.

ODBC defines a low-level set of calls which allow client applications and servers applications to exchange instructions and share data without needing to know anything about each other. It applies to any Client-Server operation, whether or not the client and server applications are resident on the same machine, or on different PC's, or even if the server is on a remote machine running a different operating system.

The Open Database Connectivity (ODBC) interface allows applications to access data from database management systems (DBMS). The interface permits maximum interoperability - a single application can access diverse back-end database management systems. An application developer can develop, compile, and ship an application without targeting a specific DBMS product. Users can then add modules called database drivers that link the application to their choice of database management systems.

The ODBC interface defines the following:

A library of ODBC function calls that allow an application to connect to a DBMS, execute SQL statements, and retrieve results.
A standard way to connect and log on to a DBMS.
A standardized representation for data types.
The Interface is flexible enabling:
An application to construct SQL statements at compile time or at run time
An application to use the same object code to access different DBMS products
An application to connect to multiple instances of DBMS products
An application to send and receive data in a format convenient to the application; the driver converts data values to the format of a specific DBMS product.

>> If you check php, you will see that it has different libraries to connect with different databases. These libraries would not have been necessary if there was ODBC on linux from the start.

As you see, there is no mention of operating system in the ODBC specification. I don't know how PHP implements things but the intent of ODBC is clearly that the driver is not dependent on the OS. If the DBMS is supported on a given platform a driver can be created for that DBMS/Platform combination. The issue, as I understand it, is not whether the platform supports ODBC, but whether the database supports it.

Regards
Andy Kramek
Microsoft MVP (Visual FoxPro)
Tightline Computers Inc, Akron Ohio, USA