[mythtv] Re: Ticket #240: DB helper classes and pgsql support (3rd attempt)

[Fernando Vilas]

#240: DB helper classes and pgsql support (3rd attempt)
 Provides database helper functions as members of a class hierarchy, and
 PostgreSQL support.

This ticket fixes the issues reported for ticket 215 as follows:

- There's database specific tests in the app, which is absolutely broken.

Added helper functions to the class hierarchy to remove these.  There should not be any more database specific checks.

 - You're breaking channel up/down ordering, and ordering in lots of other places.

I think this related to some db specific stuff in the code.  It is now fixed as part of the above.

 - The 'dbhelper' class is implemented poorly.  It should be an interface with separate classes for mysql/etc.

Done.  This also allowed me to track down some other issues I was having, so thanks for the tip.

 - lots more stuff.

Please elaborate, if any of these issues still exist, I'll be happy to fix them.

Also, still on the list for changes...
* adding lower() calls for strings, so that the case insensitivity is portable.

* finding a way to replicate MySQL's deviations from standard SQL as concerns GROUP BY clauses.

* using views to reduce complexity of code, and to increase speed by reducing the number of DELETE/INSERT calls that are made to have the same effect as a view.  Now that MySQL supports views, it may be worth it to use them.

* speed enhancements, especially in mythfilldatabase.  Replicating INSERT IGNORE by using IN clauses is slow, but quietly ignoring errors halts the INSERT operation, so we lose everything after the error.  Suggestions?

-- 
Thanks,
Fernando Vilas
fvilas at iname.com