try this,
final ArrayList<student> stud=new ArrayList<>();
if (c != null && c.getCount() > 0) {
if (c.moveToFirst()) {
do {
student stu = new student();
stu.id = c.getString(id);
stu.name = c.getString(name);
stu.age = c.getString(age);
//you need to add the Student object stu not the
//ArrayList Object stud
stud.add(stu);
} while (c.moveToNext());
mAdapter = new Adapter(stud);
recyclerView.setAdapter(mAdapter);
}
}
you are adding student object to adapter . you need to add student list to adapter . change your code like this
final List<student> stud = new ArrayList();
if (c.moveToFirst()) {
do {
student stu = new student();
stu.id = c.getString(id);
stu.name = c.getString(name);
stu.age = c.getString(age);
stud.add(stu); // add your object to list
} while (c.moveToNext());
mAdapter = new Adapter(stud);
recyclerView.setAdapter(mAdapter);
