How can I distinct a set of rows with collapsed columns in postgresql? -


for instance, have table

 id_plant | name | petals ----------+------+--------  12       | foo  |   3     13       | bar  |   3      14       | foo  |   6

i need distinct name , have array petals values. entry foo :

result :

 name | petals ------+--------  foo  | [3, 6]

use array_agg().

with my_table(id_plant, name, petals) ( values     (12, 'foo', 3),     (13, 'bar', 3),     (14, 'foo', 6) )  select name, array_agg(petals) petals my_table group name;   name | petals  ------+--------  foo  | {3,6}  bar  | {3} (2 rows)

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