[mythtv-users] From trunk to stable...

R. G. Newbury newbury at mandamus.org
Tue Nov 13 03:12:46 UTC 2007

Matt Roberts wrote:
> (I'm re-sending this with an appropriate subject line)
>> I'm considering to change fron svn trunk to 0.20-fixes branch.
>> How about mysql database? I know, that trunk has updated database schema.
>> What is easiest way to revert back? I have made much changes to settings 
>> and I don't want to loose them. Also I'd like keep all data from 
>> recordings, autoexpire etc.
>> If I drop all tables and recreate them with mc.sql, what tables I can 
>> safely recover from backup to new database? Or is there any that has no 
>> changes?
>> -Kane
> I don't know if there's an easy way to revert back, but I can tell you what I 
> did a few weeks ago after discovering that the trunk was too volatile for my 
> tastes.
> I started with the instructions for moving data to new hardware 
> (http://www.mythtv.org/docs/mythtv-HOWTO-23.html#ss23.7).  It lists the 7 
> tables that are really important to preserve.  The specific steps I took (as 
> I remember them) were:
> 1. Create a restore script as described in the "Moving Your Data to New 
> Hardware" instructions
> 2. Create a script that will create the table structure for those 7 tables as 
> they exist in the currently installed version of myth
> 3. Create a backup of the settings and channel tables.  These were for future 
> reference only, in my case.  I didn't try to directly restore them.
> 4. Drop all tables
> 5. Uninstall 0.21
> 6. Install 0.20
> 7. Execute a myth program (mythtv-setup) so that all tables get created 
> (mc.sql does not do this, it only creates the database, user, and grants some 
> privileges)
> 8. Edit the scripts created in steps 1 & 2 so they will restore the data to 
> tables with a unique name.  I used '<table_name>_21', so 'recorded' 
> became 'recorded_21', etc.
> 9. Run the create and restore scripts
> 10. Compare the column list of the 0.20 tables with that of the 0.21 tables 
> and write some "insert into 0.20_table (select columns from 0.21_table)" SQL 
> statements that only pull data from columns common to both versions.
> 11. Run the SQL statements created in step 10.
> It worked for me.  The one thing that I have left which may be of value to you 
> is my "step 10" SQL.  I assume it is still valid since I was downgrading to 
> 0.20.2.  Let me know if you'd like me to send it to you.

Flesh this out a little, with a longer explanation and post it on the 
wiki. I'm sure there are others out there who may want or need to do 
what you have done.


More information about the mythtv-users mailing list