CREATE OR REPLACE FUNCTION rankFunction(workerid_temp INTEGER) RETURNS INTEGER AS'
DECLARE
  rank integer;
  x integer;
  y integer;

Begin
  while workerid_temp != NULL

    x = chefid of current workerid_temp
    y = assume x as workerid_temp
    rank = (get new chefid with y(as workerid_temp))

    if x == NULL
      rank = 0
    else
      rank = rank + 1

return rank;
END;
' LANGUAGE plpgsql;

SELECT workerid, name, rankFunction(workerid)
FROM workers;