Re: array_agg and/or =ANY doesn't appear to be functioning as I expect

Hi Rhys,

Am 2018-01-21 um 02:42 schrieb Rhys A.D. Stewart:
> Greetings All,
> I'm having an issue which is very perplexing. The having clause in a
> query doesn't appear to be working as I expect it. Either that or my
> understanding of array_agg() is flawed.
>
> [...]
>
> with listing as (
> select start_vid, end_vid, array_agg(node order by path_seq)
> node_array, array_agg(edge order by path_seq) edge_array
> from confounded.dataset
> group by start_vid,end_vid
> having true =ALL (array_agg(truth))
> )
> select count(*) from confounded.dataset
> where node in (select distinct unnest(node_array) from listing) and
> truth = false;
>
> I would expect the above query to return 0 rows.

the answer is in your data: "node" is not a UNIQUE field, and there are
node values with multiple rows.
e.g. node=977 has one row with truth=true and one with truth=false.

So what your second query really does is "select all node values from
listing for which another entry with truth=false exists in the dataset".

Presuming that "seq" is a primary key [although not declared], you
probably meant to restrict your query on that.

Best regards,

-hannes