import pymysql
 
class LvyouPipeline(object):
  def __init__(self):
    # connection database
    self.connect = pymysql.connect(host='XXX', user='root', passwd='XXX', db='scrapy_test') # 后面三个依次是数据库连接名、数据库密码、数据库名称
    # get cursor
    self.cursor = self.connect.cursor()
    print("连接数据库成功")
 
  def process_item(self, item, spider):
    # sql语句
    insert_sql = """
    insert into lvyou(name1, address, grade, score, price) VALUES (%s,%s,%s,%s,%s)
    """
    # 执行插入数据到数据库操作
    self.cursor.execute(insert_sql, (item['Name'], item['Address'], item['Grade'], item['Score'],
                     item['Price']))
    # 提交，不进行提交无法保存到数据库
    self.connect.commit()
 
  def close_spider(self, spider):
    # 关闭游标和连接
    self.cursor.close()
    self.connect.close()

import pymysql
from twisted.enterprise import adbapi
# 异步更新操作
class LvyouPipeline(object):
  def __init__(self, dbpool):
    self.dbpool = dbpool
 
  @classmethod
  def from_settings(cls, settings): # 函数名固定，会被scrapy调用，直接可用settings的值
    """
    数据库建立连接
    :param settings: 配置参数
    :return: 实例化参数
    """
    adbparams = dict(
      host=settings['MYSQL_HOST'],
      db=settings['MYSQL_DBNAME'],
      user=settings['MYSQL_USER'],
      password=settings['MYSQL_PASSWORD'],
      cursorclass=pymysql.cursors.DictCursor  # 指定cursor类型
    )
 
    # 连接数据池ConnectionPool，使用pymysql或者Mysqldb连接
    dbpool = adbapi.ConnectionPool('pymysql', **adbparams)
    # 返回实例化参数
    return cls(dbpool)
 
  def process_item(self, item, spider):
    """
    使用twisted将MySQL插入变成异步执行。通过连接池执行具体的sql操作，返回一个对象
    """
    query = self.dbpool.runInteraction(self.do_insert, item) # 指定操作方法和操作数据
    # 添加异常处理
    query.addCallback(self.handle_error) # 处理异常
 
  def do_insert(self, cursor, item):
    # 对数据库进行插入操作，并不需要commit，twisted会自动commit
    insert_sql = """
    insert into lvyou(name1, address, grade, score, price) VALUES (%s,%s,%s,%s,%s)
    """
    self.cursor.execute(insert_sql, (item['Name'], item['Address'], item['Grade'], item['Score'],
                         item['Price']))
 
  def handle_error(self, failure):
    if failure:
      # 打印错误信息
      print(failure)

sql = """INSERT INTO video_info(video_id, title) VALUES("%s","%s")""" % (video_info["id"],pymysql.escape_string(video_info["title"]))