Absolutely, I would backup the database first .. your idea of using a two pass method would work .. would I do that with the weewx database utility or some linux based sql app like DB Browser for SQLite?
On Wednesday, July 31, 2024 at 10:45:47 AM UTC+12 p q wrote: > Do yourself a favor and make a backup copy. Test out whatever method you > chose on the copy. > > As to the query, I think you could fill the Signal field with 0.0 and then > do an UPDATE SQL query where outTemp > 10.0. You can find the SQL syntax > online. > > On Tue, Jul 30, 2024 at 3:30 PM Craig Young <craig.y...@gmail.com> wrote: > >> WeeWx version: 4.10.2 >> DB: SQLite3 >> >> What is the best method for recalculating an item in the entire >> database? Specifically, I want to do this: >> >> signal4 = 1.0 if outTemp < 10.0 else 0.0 >> >> So I want the DB update method to look at each record and if the >> temperature (in that record) is less than 10.0 C then set the signal4 value >> in that record to 1.0, otherwise, set the signal4 value to 0.0. >> >> Do I use wee_database --calc missing? >> or some other method? >> >> There are currently 575,000 records in the database so I really don't >> want to mess this up. I assume I need to stop WeeWx while doing this? >> >> Craig >> >> -- >> You received this message because you are subscribed to the Google Groups >> "weewx-user" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to weewx-user+...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/weewx-user/df5146de-9a51-4c05-888a-17a663d774f4n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/weewx-user/df5146de-9a51-4c05-888a-17a663d774f4n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > Peter Quinn > (415)794-2264 <(415)%20794-2264> > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/119eea81-a564-4b8c-b84f-3b9bb857e6d6n%40googlegroups.com.
