On Thu, Apr 20, 2017 at 3:56 PM, jonathan vanasco <postgres@2xlp.com> 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)...