Change query checking method

@@ -30,7 +30,7 @@ async def send_face(face_list, image_list):
     async with websockets.connect(uri) as websocket:
         for face, image in zip(face_list, image_list):
             #type: np.float32
-            send = json.dumps({'action': 'register', 'student_id':'2014104149', 'student_name':'정해갑', 'MTCNN': face.tolist()})
+            send = json.dumps({'action': 'register', 'student_id':'2014101898', 'student_name':'김다솜', 'MTCNN': face.tolist()})
             await websocket.send(send)
             recv = await websocket.recv()
             data = json.loads(recv)

@@ -86,10 +86,10 @@ async def thread(websocket, path):
 
                 # 학생을 찾음
                 sql = "SELECT student_id FROM student WHERE student_id = %s;"
-                cursor.execute(sql, (student_id))
+                rows_count = cursor.execute(sql, (student_id))
 
                 # DB에 학생이 없으면 등록
-                if not cursor.fetchone():
+                if rows_count == 0:
                     sql = "INSERT INTO student(student_id, student_name) VALUES (%s, %s)"
                     cursor.execute(sql, (student_id, student_name))
                     sql = "INSERT INTO lecture_students(lecture_id, student_id) VALUES (%s, %s)"
@@ -141,10 +141,10 @@ async def thread(websocket, path):
                     # 인증 성공
                     # 오늘 이미 출석 됐는지 확인
                     sql = "SELECT DATE(timestamp) FROM student_attendance WHERE (lecture_id=%s) AND (student_id=%s) AND (DATE(timestamp) = CURDATE());"
-                    cursor.execute(sql, ('0', verified_id))
+                    rows_count = cursor.execute(sql, ('0', verified_id))
                     
                     # 출석 기록이 없는 경우에만
-                    if not cursor.fetchone():
+                    if rows_count == 0:
                         # 테이블 맨 뒤에 datetime attribute가 있음. 서버 시간 가져오게 default로 설정해둠.
                         sql = "INSERT INTO student_attendance(lecture_id, student_id, status) VALUES (%s, %s, %s)"
                         # TODO: attend / late 처리