Error Code: 1442. problem z triggerem Opcje

[djszaki]

stworzyłem taki prosty trigger:
CREATE TRIGGER data_dodania
BEFORE INSERT ON pracownik
FOR EACH ROW update pracownik
SET imie = "Jan";

kiedy probuję dodać rekord np
INSERT INTO pracownik (id_pracownika) VALUES (1);


otrzymuje komunikat:
Error Code: 1442. Can't update table 'pracownik' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.

o co chodzi ?

[djszaki]

CREATE TRIGGER data_dodania
after INSERT ON pracownik
FOR EACH ROW update pracownik
SET imie = "Jan";

i dodam id to taki sam komunikat się pojawia,

Error Code: 1442. Can't update table 'pracownik' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.