I have found my error. Some days ago I change the order of field in
table LECIONAR. (ID_PARCEIRO, ID_DISCIPLINA) TO
(ID_DISCIPLINA,ID_PARCEIRO). But the order in primary key I didn't
change, and the order of primary key is the old orde of the table. So
I will change the primary key. Thank you.

> Do you have a unique or primary key constraints on columns
> ID_DISCIPLINA & ID_PARCEIRO in table LECIONAR?
>
> If not, how do you expect the database engine to be able to
> uniquely identify the "parent" row?