[mythtv-users] Database upgrade 0.21 -> 0.22: issue to avoid

[Michael T. Dean]

On 11/16/2009 04:01 AM, James Warden wrote:
> I went through an upgrade from mythtv 0.21 to 0.22 yesterday and found an issue with the following (probably already mentioned somewhere else but this is how I fixed it):
>
> the dtv_multiplex and channelscan_dtv_multiplex tables cannot be upgraded from db schema 1230 to 1231 and makes the whole upgrade fail.
>
> This is because the table already contains a field (mysql column) that the upgrade is trying to add again when upgrading to 1231.
>
> So what I did is to make a backup (mysqldump) of DB at schema 1230, remove the screwing field from the dump (it is an ASCII file) when it is trying to INSERT it in these particular tables, retore the modified DB, and upgrade again.
>
> It worked pretty nicely. I can give some more technical details / howto when I am at home if someone needs it.

You restored a 0.21-fixes DB backup /on top of/ a 0.22-fixes DB schema.  
That means that MySQL converted any data to fit (and may have broken 
your data).  That means you should /immediately/ go back to your 
0.21-fixes database backup and restore it properly and then let MythTV 
upgrade it properly.

http://www.gossamer-threads.com/lists/mythtv/users/405443#405443

(Specifically, read the section, "If you're not doing an "in-place" 
upgrade (so you need to restore your DB backup), it is critical that you 
DROP any existing database /before/ restoring your database backup." )

and http://svn.mythtv.org/trac/ticket/6923#comment:4

If you don't do this, all of your data is suspect, and bad things may 
happen.

Mike