Re: The value in @@DATADIR is wrong it doesn't match the value in my.ini

[Peter Brawley]

> mysql is looking in the wrong place

The 5.6 installation put a starting data folder in the default location for Windows, C:\ProgramData\MySQL\MySQL Server 5.6\DATA\.

Unless you move or deleted it, your 5.5 data should still be at C:/MySQLdata/Data

> What's the syntax for updating @@DATADIR via SQL ??

It's not SQL. It's a setting in my.ini and/or a command option for mysqld.exe.

Before installing mysql 5.6, you should have created a full logical backup of all your DBs ...

https://dev.mysql.com/doc/refman/5.6/en/upgrade-before-you-begin.html

https://dev.mysql.com/doc/refman/5.6/en/windows-upgrading.html

... and reviewed changes in your new version ...

https://dev.mysql.com/doc/refman/5.6/en/upgrading-from-previous-series.html

If you did that backup, now you should import it into 5.6. If not, there's a mess to clean up.