"David G. Johnston" <david.g.johnston@xxxxxxxxx> writes: > On Fri, May 5, 2023 at 6:55 AM Sky Lendar <skylendar@xxxxxxxxx> wrote: >> Notice that 12 is missing in the list. > Since your DISTINCT ON *subquery* doesn't specify an ordering which of > those two are chosen as the representative record for M31 is > non-determinstic. > If you want to ensure the lowest valued nb is chosen you need to sort the > *subquery*. The "weather_reports" example here might help clarify this for you: https://www.postgresql.org/docs/current/sql-select.html regards, tom lane
