Azkaban

I have a database that logs events and it's growing too big.

I'd like to set up a cron to reduce the records. Thet able looks like this

eventid | date | eventname | error | type
==================================
1 | 1/1/01| exception | HD | 1
2 | 1/5/01| exception | HD | 1
3 | 1/5/01| shutdown | SD | 3
4 | 1/11/01| exception | HD | 2
5 | 1/12/01| exception | HD | 4
6 | 1/16/01| exception | ED | 2
==================================


If you look at the data above, the only data I care about keeping really is when the eventname and error are the same. So in this case, I'd like to roll up lines 1,2,4,5 into one line, with the eventid, date and type that should be kept is the last one. So it would be line 5 that is kept and lines 1,2,4 delete. How can I do that in mysql/php?

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