On 2024-05-18 17:12 +0200, David G. Johnston wrote:
> Too lazy to find the docs right now but what you are observing is basically
> an operator precedence effect. The comma join hasn’t happened at the time
> the left join is evaluated and so other tables in the comma join cannot
> appear in the on clause of the left join. Placing everything inside a
> single from slot and moving the conditions to the where clause removes
> changes the precedence aspect so that the cross join does indeed evaluate
> prior to the left join.
Thanks David. The docs on table expressions clarify the precedence:
https://www.postgresql.org/docs/16/queries-table-expressions.html#QUERIES-FROM
I'm using SQL for 17 years now and yet I still forget that joins are
table expressions m(
--
Erik