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
