if I were doing it, I would use SQLite to execute the queries and then I would check my work with DB Browser.
I think you may have misunderstood my backup comment. I would practice on a copy of my database. Once I had the queries correct, then I'd stop Weewx, make another backup of the database to be safe, perform the operation, and then restart Weewx. If you're sure you won't mess up, you can skip practice and the extra backup. On Tue, Jul 30, 2024 at 4:09 PM Craig Young <[email protected]> wrote: > 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 <[email protected]> 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 [email protected]. >>> 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/119eea81-a564-4b8c-b84f-3b9bb857e6d6n%40googlegroups.com > <https://groups.google.com/d/msgid/weewx-user/119eea81-a564-4b8c-b84f-3b9bb857e6d6n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- Peter Quinn (415)794-2264 -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/CAA1SM21kd9gXV_oNh9vzuYomYwsu8K_RjN24fHzO588P5CBt8w%40mail.gmail.com.
