Should the students have a job while studying

I can't exactly say, should have students a job while studying or not.
In my opinion, while their study in the school or in the university they should concentrate on learning and sudying.
If sudents need money, they can ask their parents to help, and their mothers and dads will give money to buy what children want.
On the other hand if there is real problem with money in the family, it is better to earn money yourself.
So, I can't  content that they should or they should not..
I think having a job while studying depends on sudent's wishes and do they really need this money! :)