老师我运行到这一步然后就出现一大堆错误，一脸茫然，试了很多方法都不行，也看了你的代码，找不到错误在哪

class ZhihuAnswerItem(scrapy.Item):
zhihu_id = scrapy.Field()
url = scrapy.Field()
question_id = scrapy.Field()
author_id = scrapy.Field()
content = scrapy.Field()
praise_num = scrapy.Field()
comments_num = scrapy.Field()
create_time = scrapy.Field()
update_time = scrapy.Field()
crawl_time =scrapy.Field()

def get_insert_sql(self):
    insert_sql = """
        insert into zhihu_answer(zhihu_id, url, question_id, author_id, content, praise_num, comments_num, create_time,
        update_time, crawl_time)
        VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
    """
    create_time = datetime.datetime.fromtimestamp(self["create_time"])
    update_time = datetime.datetime.fromtimestamp(self["update_time"])
    params = list()

    params.append(self["zhihu_id"][0])
    params.append(self["url"][0])
    params.append(self["question_id"][0])
    params.append(self["author_id"][0])
    params.append(self["content"][0])
    params.append(self["praise_num"][0])
    params.append(self["comments_num"][0])
    params.append(self["create_time"][0])
    params.append(self["update_time"][0])
    params.append(self["crawl_time"][0])

    return insert_sql,params