On 10/29/2015 7:18 PM, David Blomstrom wrote:
Can anyone tell me how to write the query described @
http://stackoverflow.com/questions/33402831/count-descendants-in-hierarchical-query
?
The answer's very thorough, but I don't know how to string two queries
and a function together like that. This doesn't work:
$sql = "select * from gz_life_mammals;";
create function tax_rank(id integer) returns text as $$
select case id
when 1 then 'Classes'
when 2 then 'Orders'
when 3 then 'Families'
when 4 then 'Genera'
when 5 then 'Species'
end;
$$ language sql;
$sql = "with recursive hier(taxon,parent_id) as (
select m.taxon, null::integer
from gz_life_mammals m
where taxon='Mammalia' --<< substitute me
union all
select m.taxon, m.parent_id
from hier, gz_life_mammals m
where m.parent=hier.taxon
)
select tax_rank(parent_id),
count(*) num_of_desc
from hier
where parent_id is not null
group by parent_id
order by parent_id;";
Thanks.
The function is created once (like with your create tables). Don't use
it in PHP.
Your PHP should only be like:
> $sql = "with recursive hier(taxon,parent_id) as (
> select m.taxon, null::integer
> from gz_life_mammals m
> where taxon='Mammalia' --<< substitute me
> union all
> select m.taxon, m.parent_id
> from hier, gz_life_mammals m
> where m.parent=hier.taxon
> )
> select tax_rank(parent_id),
> count(*) num_of_desc
> from hier
> where parent_id is not null
> group by parent_id
> order by parent_id;";
$result = pg_query($dbh, $sql);
while ($row = pg_fetch_array($result)) {
etc
etc
-Andy
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