Re: Query-Regarding

[Peter Brawley]

Is this what you mean?

update nmp.sales a
join nmp.purchase b using(barcode,department)
set a.act_days_to_sell=(timestampdiff(day,b.purentrydate,a.entrydate));

If you're not sure, first run it as a Select query to check that it's finding the desired rows ...

select a.act_days_to_sell,a.entrydate,b.purentrydate,timestampdiff(day,b.purentrydate,a.entrydate) as diff
from nmp.sales a
join nmp.purchase b using(barcode,department);