X extension if I want to change to another school

Hello,

I am going to China to learn madarin for 4 months, but my plan is to learn mandarin for 2 years. I already applied to a school and will probably be given a student visa for the amount of time I will be staying in that school, which is 4 months. I wanted to apply to another schoolto stay 1 year in that school, but the application deadline wouldnt allow me. My question is, if I go to China and apply and get accepted in the school that I wanted, would they extend my visa there or would I need to come back to my country to get another X for the new school?