I have the tables: Class, Discipline, Teacher, Evaluation, Teacher-Item, Pupil.

I want to make a restriction so that when a teacher makes a mark, he could not put them on other (classes, disciplines) in which he will not introduce, but only where he teaches. Can you tell me how to do this? (I, understand, that it is necessary to make the trigger. Here only I can not understand how)

Scheme

  • The scheme is drawn "on a whim", without the normal analysis. Hence the problem (if it is the first, then a hundred pounds is not the last). Erase everything and start over, but this time by science. - Akina

0