I want a 32bit bit application (running on Windows 7 64bit) to connect to MySQL 5 64bit through ODBC.
Does the MySQL ODBC connector have to be 32 or 64 bit?
Does the MySQL ODBC connector's register size have to match the application's or MySQL's? Windows 7 64bit can handle 32bit as well as 64bit connectors - so this does not matter.
(verified with R 32bit and 64bit / Windows 7 64bit / MySQL 5 32bit.)
Only the application's architecture (32bit or 64bit) that connects via the ODBC adapter does matter and has to be matched by it.
Windows 7 64bit can handle both 32bit and 64bit ODBC connectors (different data source managers though)
To MySQL 5 32bit you can connect with a 32bit as well as with a 64bit ODBC connector.
You cannot link a 32 bit application to a 64 bit ODBC driver so you have no choice if your app is 32 bit. Whether the 32 bit ODBC driver talks to the 64 bit mysql is another