snake_case_to_camelCase.sql

create function lcfirst(word text)
returns text
language plpgsql
immutable
as $$
begin
  return lower(left(word, 1)) || right(word, -1);
end;
$$;

create function camel_case(snake_case text)
returns text
language plpgsql
immutable
as $$
begin
  return
    replace(
      initcap(
        replace(snake_case, '_', ' ')
      ),
      ' ', ''
    );
end;
$$;

select lcfirst(camel_case('snek_snek_snek'));
   lcfirst    
--------------
 snekSnekSnek