Store select query's output in one array in postgres

There are two ways. One is to aggregate:

SELECT array_agg(column_name::TEXT)FROM information.schema.columnsWHERE table_name = 'aean'

The other is to use an array constructor:

SELECT ARRAY(    SELECT column_name     FROM information_schema.columns     WHERE table_name = 'aean')

I'm presuming this is for plpgsql. In that case you can assign it like this:

colnames := ARRAY(    SELECT column_name    FROM information_schema.columns    WHERE table_name='aean');

I had exactly the same problem. Just one more working modification of the solution given by Denis (the type must be specified):

SELECT ARRAY(SELECT column_name::textFROM information_schema.columnsWHERE table_name='aean')

Casting to the datatype "TEXT" will ensure that your queries will run without any problem.In plpgsql when we assign to a array variable, we need not use the type casting. My requirement was to get a CSV of all the column names of a particular table. I'd used the following code in plpgsql.

Declare col_list varchar[]:=NULL;cols varchar:=NULL;Begin    col_list := ARRAY(select t.name from frm_columns t where t.tname='emp_mstr');    cols := array_to_string(col_list,',');    return cols;End;