On Thu, Apr 20, 2017 at 3:56 PM, jonathan vanasco <postgres@xxxxxxxx> wrote:
thanks all!On Apr 20, 2017, at 6:42 PM, David G. Johnston wrote:Subqueries can see all columns of the parent. When the subquery actually uses one of them it is called a "correlated subquery".i thought a correlated subquery had to note that table/alias, not a raw column. I guess i've just been adhering to good form.On Apr 20, 2017, at 6:43 PM, Tom Lane wrote:Cautious SQL programmers qualify all references inside sub-selects to avoid getting caught by this accidentally.is there a syntax to qualify a reference to lock a subquery to the current scope (disable looking at the parents)? that's how I got caught on this by accident.
Like Tom said, "qualify all references":
...(SELECT example_a__rollup.bar_id FROM example_a__rollup)...
Or shortened with alises:
...(SELECT x.bar_id FROM example_a__rollup x)...
Cheers,
Steve
