In reply to Design Engineer:
Sorry, forgot that the array concatenation syntax does not allow the nested implicit assignment pattern. You would have to write
base ={student_data'{10,"John",2,1},student_data'{11,"Paul",2,0},student_data'{12,"George",2,0}, student_data'{13,"Ringo",2,0}};
But you can also just change the outer concat into an assignment pattern
base ='{'{10,"John",2,1},'{11,"Paul",2,0},'{12,"George",2,0}, '{13,"Ringo",2,0}};