How about weak entities and mysql?
Is there any possiblility i can create them?
If yes, how? I googled but it seems theres nothing to find about it (??)

Maybe i just don't know how weak entities are called usually...
I mean an entity's foreign key is part of some other entities primary key. So in the key there is some kind of suffix, an addition.

This indicates that the "child" entity cannot exist without the "parent" one.

Any suggestions?

yes, you can do this in mysql -- ordinary primary/foreign keys

and the nice thing is, in mysql, you can decide to implement your tables in such a way that the foreign keys are not enforced

that's really weak!!