psql function: append one dimensional array to a two dimensional array using array_append

Question

I tried to append an one dimensional array to a two dimensional array using array_append in psql function. I defined count_values as output by out count_values integer[][], cout_value as variable in declare section by count_value integer[], and tried to use count_values := array_append(count_values, count_value), but the error function array_append(integer[], integer[]) does not exist poped up.

            if ...
            else
                count_value:= array_append(count_value, 0);
            end if;
            index:= index + 1;
        end loop;
        
        count_values:= array_append(count_values, count_value);
    end loop;
...

Answer 1

See this fiddle

create function f() returns integer[][]
as $$
declare
    count_value integer[] = '{5,6}';
    count_values integer[][] = '{{1,2},{3,4}}';
begin
  return Array_cat(count_values,count_value);
end; $$
language plpgsql;

or, starting with an empty array,

create function f() returns integer[][]
as $$
declare
    count_value integer[] = '{5,6}';
    count_values integer[][] ;
    new_cvs integer[][];
begin
  if count_values is null
  then new_cvs = array_cat(ARRAY[]::integer[][],ARRAY[count_value]);
  else new_cvs = Array_cat(count_values,count_value);
  end if ;
  return new_cvs;
end; $$
language plpgsql;

see another fiddle