--CODE
CREATE TABLE test_tbl (accn varchar(10) PRIMARY KEY, method TEXT, species VARCHAR(30), lat NUMERIC,
lon NUMERIC, location TEXT, larger_region TEXT, coords BOOLEAN DEFAULT TRUE);

FETCH FORWARD 1 FROM test_tbl;

accn     |  method  |        species    |   lat    |    lon   |         location           | larger_region | coords
---------+----------+-------------------+----------+----------+----------------------------+---------------+---------
EU336944 |  Isolate | Dysidea granulosa | 10.07704 | 73.63238 | Lakshadweep Islands, India | Indian EEZ    | t

CREATE TABLE test_view_tbl ( species VARCHAR(30) NOT NULL, no_ind BIGINT NOT NULL, method TEXT NOT NULL, location TEXT NOT
NULL, larger_region TEXT NOT NULL );

CREATE FUNCTION test_view() RETURNS SETOF test_view_tbl AS $$
SELECT DISTINCT ON (species, method, location, larger_region) species, count(species), method, location, larger_region
FROM test_tbl
GROUP BY species, method, location, larger_region
ORDER BY species;
$$ LANGUAGE sql

SELECT * FROM test_view();

       species      | no_ind | method  |               location               | larger_region
  ------------------+--------+---------+--------------------------------------+---------------
  Dysidea granulosa |      6 | Isolate | Kavaratti Island, Lakshadweep, India | Indian EEZ
  Dysidea granulosa |     13 | Isolate | Lakshadweep Islands, India           | Indian EEZ

ALTER TABLE test_view_tbl ADD COLUMN coords BOOLEAN DEFAULT TRUE;

CREATE FUNCTION test_view() RETURNS SETOF test_view_tbl AS $$
SELECT DISTINCT ON (species, method, location, larger_region) species, count(species), method, location, larger_region,
CASE WHEN lat IS NULL THEN coords IS FALSE ELSE TRUE
END
FROM test_tbl
GROUP BY species, method, location, larger_region, lat, coords
ORDER BY species;
$$ LANGUAGE sql

SELECT * FROM test_view();

      species      | no_ind | method  |               location               | larger_region | coords
-------------------+--------+---------+--------------------------------------+---------------+--------
 Dysidea granulosa |      6 | Isolate | Kavaratti Island, Lakshadweep, India | Indian EEZ    | t
 Dysidea granulosa |      3 | Isolate | Lakshadweep Islands, India           | Indian EEZ    | t