Re: Counting the number of repeated phrases in a column

On Wed, Jan 26, 2022 at 5:23 PM Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
>
> with s as (select 'Hello World Hello World' as sentence)
> select
> phrase,
> array_upper(string_to_array((select sentence from s), phrase), 1) -
> 1 as occurrances
> from
> (
> select array_to_string(x, ' ') as phrase
> from
> (
> select distinct v[a:b] x
> from regexp_split_to_array((select sentence from s), ' ') v
> cross join lateral generate_series(1, array_upper(v, 1)) a
> cross join lateral generate_series(a + 1, array_upper(v, 1)) b
> ) q
> ) q;

Simplified to:
select distinct array_to_string(v[a:b], ' ') phrase, count(*) as occurrences
from regexp_split_to_array('Hello World Hello World', ' ') v
cross join lateral generate_series(1, array_upper(v, 1)) a
cross join lateral generate_series(a + 1, array_upper(v, 1)) b
group by 1;

phrase │ occurances
─────────────────────────┼────────────
World Hello │ 1
Hello World Hello │ 1
Hello World │ 2
Hello World Hello World │ 1
World Hello World │ 1

merlin