Thank you heaps Walt .. exactly what I was looking for. Craig
On Wednesday, July 31, 2024 at 11:12:27 PM UTC+12 wfs...@gmail.com wrote: > You can do this with the sqlite3 utility program. I believe the sql > update statement you want is: > > update archive set signal4 = case when outtemp < 10.0 then 1.0 else 0.0 > end; > > I tried it on a copy of my database, see attached. > > Walt > > On Tuesday, July 30, 2024 at 7:03:20 PM UTC-5 Craig Young wrote: > >> Good advice Peter .. I will give this a try. >> >> Craig >> >> On Wednesday, July 31, 2024 at 11:18:26 AM UTC+12 p q wrote: >> >>> 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 <craig.y...@gmail.com> >>> 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 <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+...@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 >>>> >>>> <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 <(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/7ab0aa5f-a172-4f3a-81f7-208fbae82f27n%40googlegroups.com.
