Re: Counting the number of repeated phrases in a column

[Rob Sargent]

On 1/27/22 10:03, Merlin Moncure wrote:

On Wed, Jan 26, 2022 at 5:23 PM Merlin Moncure<mmonc...@gmail.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

And since we're looking for repeated phrases maybe add

   having count(*) > 1