InterfaceError:(sqlte3.InterfaceError)Er?400报错

InterfaceError:(sqlte3.InterfaceError)Error binding parameter 0? 400 报错

最近在学习scrapy爬虫，爬取别人博客上的文章标题。如果不加数据库，能够很好的输出结果，虽然排版不好看，但是使用sqlalchemy存储数据，一直出错，错误提示所图片所示：

我的item['title']是通过以下的解析式来的：

item['title'] = sel.xpath('//*[@class="link_title"]/a/text()').extract()

from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
DeclarativeBase = declarative_base()

def db_connect():
    return create_engine('sqlite:///./sqlalchemy.db',echo = True)

def create_myblog_table(engine):
    DeclarativeBase.metadata.create_all(engine)

class MyBlog(DeclarativeBase):
    __tablename__ = 'myblog'

    id = Column(Integer, primary_key = True)
    title = Column('title', String(200))

from sqlalchemy.orm import sessionmaker
from model import MyBlog, db_connect, create_myblog_table


class MyblogPipeline(object):
    def __init__(self):
        engine = db_connect()
        create_myblog_table(engine)
        self.Session = sessionmaker(bind = engine)

    def process_item(self, item, spider):
        session = self.Session()
        myblog=MyBlog(**item)
        session.add(myblog)
        session.commit()
        return item