Update roll book

@@ -166,7 +166,7 @@ def verify():
 def tempAttendance():
    attendance_db = pymysql.connect(read_default_file="./DB.cnf")
    cursor = attendance_db.cursor(pymysql.cursors.DictCursor)
-   sql = "SELECT ls.student_id, s.student_name, sa.status FROM lecture_students AS ls LEFT JOIN student_attendance AS sa ON ls.student_id = sa.student_id LEFT JOIN student AS s ON ls.student_id = s.student_id;"
+   sql = "SELECT ls.student_id as student_id, s.student_name as student_name, ifnull(sa.status, 'absent') as status FROM lecture_students AS ls LEFT JOIN student_attendance AS sa ON ls.student_id = sa.student_id LEFT JOIN student AS s ON ls.student_id = s.student_id;"
    mycursor.execute(sql)
    data = mycursor.fetchall()
    return render_template('attendance.html', output_data = data)