@films_bp.route('/avg_rating_num_by_avg_rates', methods=['GET']) def avg_rating_num_by_avg_rates(): #返回按年统计的每年电影的平均得分，,返回的json数据格式如下所示 try: conn = pymysql.Connection( host='localhost', port=3306, user='root', passwd='21591314cxk' ) cur = conn.cursor() cur.execute('select rate,rating_num from movie.movieinfo where rating_num > 500') dic = cur.fetchall() conn.commit() cur.close() return jsonify(dict(dic)) except Exception as e: logging.error('Error occurred while retrieving students from the database. Error message: {}'.format(str(e))) return jsonify({"error": str(e)})这段代码只返回一个评分结果对应的数据，一旦查找到一个评分就不会继续查找同样评分对应的数据，而我想获取所有数据，请改正并优化代码。

可以将查询结果按照评分进行分组，然后再遍历每个分组获取对应的评分和评分数量，最后组成字典返回即可。以下是修改后的代码示例：

@films_bp.route('/avg_rating_num_by_avg_rates', methods=['GET'])
def avg_rating_num_by_avg_rates():
    try:
        conn = pymysql.Connection(
            host='localhost',
            port=3306,
            user='root',
            passwd='21591314cxk'
        )
        cur = conn.cursor()
        cur.execute('SELECT rate, COUNT(*) as rating_num FROM movie.movieinfo WHERE rating_num > 500 GROUP BY rate')
        rows = cur.fetchall()
        conn.commit()
        cur.close()
        result = {}
        for row in rows:
            result[row[0]] = row[1]
        return jsonify(result)
    except Exception as e:
        logging.error('Error occurred while retrieving students from the database. Error message: {}'.format(str(e)))
        return jsonify({"error": str(e)})

这样修改后，查询结果会按照评分进行分组，返回的字典中每个键值对对应一个评分和该评分对应的数量。