ADD histogram function for metabase

This commit is contained in:
Nathan Dwarshuis 2021-05-30 00:02:27 -04:00
parent 9910efe692
commit 59e5edc066
1 changed files with 37 additions and 0 deletions

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@ -4,6 +4,43 @@ as $$
select ts::time at time zone 'US/Eastern';
$$ language SQL;
CREATE OR REPLACE FUNCTION histogram(tname text, cname text, width int)
RETURNS TABLE(bin_number int, bin_interval text, count bigint)
AS $func$
BEGIN
RETURN QUERY EXECUTE format('
with recursive
no_bins_t as (
select min(floor(a.%1$s/%2$s)*%2$s)::int as bin_number from %3$s a
union all
select bin_number + 1 as bin_number from no_bins_t
where
bin_number < (select max(floor(a.%1$s/%2$s)) + 1 from %3$s a)
)
select
bin_number,
concat(bin_number*%2$s, ''-'', bin_number*%2$s + %2$s - 1) as bin_interval,
case when count is null then 0 else count end as count
from no_bins_t
left join
(select
floor(a.%1$s/%2$s)*%2$s as ab_floor,
count(*) as count
from %3$s a
group by ab_floor
order by ab_floor) as binned
on no_bins_t.bin_number*%2$s=binned.ab_floor
order by no_bins_t.bin_number;',
cname,
width,
tname
);
END
$func$ LANGUAGE plpgsql;
create or replace procedure make_vis_tables()
language plpgsql
as $$