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Re^6: find difference in dates/items in same column

by zerocred (Beadle)
on Nov 15, 2008 at 22:04 UTC ( #723854=note: print w/ replies, xml ) Need Help??


in reply to Re^5: find difference in dates/items in same column
in thread find difference in dates/items in same column

Great! 120k rows in 10 seconds on MySQL on Linux and 17 seconds on MS Access
(there's no 'day' parameter mysql's DATEDIFF - when i cracked that it worked!)

select brand, id, date, datediff( date, (select max(T2.date) from test as T2 where T1.brand = T2.brand and T2.date < T1.date) ) from test as T1 order by brand, id
Your solution is vastly superior (simpler/faster) to the one in MYSQL cookbook or any SQL forum/discussion I have seen!
Thanks that's great!


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