MORE INFORMATION
For the purposes of this article, the following is assumed:
- You set up a data source for the SQL Server driver called mysqlsvr.
- The data source is located on a server called Unixmc.
- You are connecting to a Sybase SQL Server table on Unix whose
address is 11.1.4.40,3180.
- The net-library you are using is wdbftptc.dll.
Given these assumption, if the setup was done correctly, the Odbc.ini
file will have the following entry in the [ODBC Data Sources] section:
mysqlsvr=SQL Server
There will be a section called [mysqlsvr] in the Odbc.ini and it will
have entries of the following form:
DRIVER=c:\windows\system\sqlsrvr.dll
Description=SQL\Server on server Unixmc
OemToAnsi=No
Network=wdbftptc
Address=11.1.4.40,3180
The DRIVER entry points to the location of the SQL Server driver. It is
located on the System subdirectory of the Windows directory.
The Description entry describes what kind of a data source this is. This is
something that you can change when setting up the data source by using ODBC
Administrator.
The OemToAnsi entry indicates whether conversion needs to be done from the
OEM code page to the ANSI code page. Note that this is not the same as the
translation DLL.
The Network entry indicates the name of the net-library.
The Address entry indicates the network address.
The WIN.INI file will have the following entry in its [SQLSERVER] section:
mysqlsrvr=wdbftptc,11.1.4.40,3180
When you run a SQLConnect or SQLDriverConnect command and choose to connect
to the mysqlsvr data source, the Driver manager looks in the ODBC.INI file
to find the name and location of the SQL Server driver. It looks for the
DRIVER entry described above and loads it into memory.
Next, the SQL Server driver looks in the Win.ini file's [SQLSERVER] section
for mysqlsvr entry where it picks up the name of the net-library. Then it
loads the net-library name (wdbftptc in this case) into the memory. Next,
it looks at the entry again to get the address of the server which it
passes on to the net-library. If there is no address following the name of
the net-library, it passes the name of the data source to the net-library,
as the network address.
Db-library users should note that unlike W3dblib.dll, the SQL Server driver
does not look at the dsquery entry unless dsquery is a data source in the
Odbc.dll file.
If you are using Microsoft Access, this sequence of operations takes place
when you link (attach) a SQL Server table. If you are using Microsoft
Visual Basic, it takes place in response to the OpenDataBase call.