MYSQL TRIGGER subquery update

Question

I'm new working with my SQL, and I develop a trigger in SQLSERVER that is running perfect, now I'm trying to convert it, to use in Mysql, but doesn't work and I don't know what to do.

here's the code:

CREATE TRIGGER tg_test AFTER UPDATE ON  YET FOR EACH ROW

INSERT INTO CONTROLETRIGGER(idAluno, idNivel)
values(NEW.IdAluno, NEW.idNivel);


UPDATE HistoricoNivel AS E
join(
select max(h.idNivel) Nivel, h.idAluno
from HistoricoNivel h
join CONTROLETRIGGER v on h.idaluno = v.idaluno
WHERE h.dtFim is null
group by h.idAluno
)X on E.idAluno = X.idAluno and E.idNivel= X.Nivel
join CONTROLETRIGGER vi on vi.idaluno = E.idAluno
set E.dtFim = case when X.idnivel <> vi.idNivel then CURRENT_DATE() else null end

Please, what i'm doing wrong ?

Tks.

Answer 1

The X subquery does not have a field called idnivel , so the case statement will not compile.

I assume what you want here is nivel , which would make the full trigger;

CREATE TRIGGER tg_test AFTER UPDATE ON  YET FOR EACH ROW
 INSERT INTO CONTROLETRIGGER(idAluno, idNivel) VALUES (NEW.IdAluno, NEW.idNivel);
 UPDATE HistoricoNivel AS E
 JOIN(
  SELECT MAX(h.idNivel) Nivel, h.idAluno
  FROM HistoricoNivel h
  JOIN CONTROLETRIGGER v ON h.idaluno = v.idaluno
  WHERE h.dtFim IS NULL
  GROUP BY h.idAluno
 ) X 
 ON E.idAluno = X.idAluno AND E.idNivel= X.Nivel
 JOIN CONTROLETRIGGER vi ON vi.idaluno = E.idAluno
 SET E.dtFim = CASE WHEN X.nivel <> vi.idNivel THEN CURRENT_DATE() ELSE NULL END
//

See it compile here .