76 lines
2.8 KiB
Python
76 lines
2.8 KiB
Python
# Define your item pipelines here
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#
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# Don't forget to add your pipeline to the ITEM_PIPELINES setting
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# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html
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# useful for handling different item types with a single interface
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import mysql.connector
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from scrapy.exceptions import DropItem
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from .items import NewsItem
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from .settings import MYSQL_USERNAME, MYSQL_PASSWORD, MYSQL_HOST, MYSQL_PORT, MYSQL_DATABASE
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class DecspiderPipeline:
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def open_spider(self, spider):
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# 连接数据库
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self.conn = mysql.connector.connect(user=MYSQL_USERNAME, password=MYSQL_PASSWORD, host=MYSQL_HOST, database=MYSQL_DATABASE, port=MYSQL_PORT)
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self.cursor = self.conn.cursor()
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# 动态生成表名
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self.table_name = f'{spider.settings.get("BOT_NAME")}_{spider.name}'
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spider.log(f'Dataset name: {self.table_name}')
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# 检查表是否存在，如果不存在就创建表
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self.cursor.execute(f"""
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CREATE TABLE IF NOT EXISTS `{self.table_name}` (
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id INT AUTO_INCREMENT PRIMARY KEY
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)
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""")
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# 获取当前表的列信息
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self.cursor.execute(f"SHOW COLUMNS FROM `{self.table_name}`")
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existing_columns = {row[0] for row in self.cursor.fetchall()}
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# 获取 NewsItem 字段信息
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item_columns = set(NewsItem.fields.keys())
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# 添加 NewsItem 字段到表中
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for column in item_columns:
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if column not in existing_columns:
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self.cursor.execute(f"ALTER TABLE `{self.table_name}` ADD COLUMN `{column}` TEXT")
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spider.log(f'Added column `{column}` to `{self.table_name}` table')
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# 删除表中不存在于 NewsItem 中的字段
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for column in existing_columns:
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if column not in item_columns and column != 'id':
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self.cursor.execute(f"ALTER TABLE `{self.table_name}` DROP COLUMN `{column}`")
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spider.log(f'Dropped column `{column}` from `{self.table_name}` table')
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self.conn.commit()
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def close_spider(self, spider):
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self.conn.close()
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def process_item(self, item, spider):
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if isinstance(item, NewsItem):
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# 插入数据
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columns = ', '.join(item.keys())
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placeholders = ', '.join(['%s'] * len(item))
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sql = f"INSERT INTO `{self.table_name}` ({columns}) VALUES ({placeholders})"
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try:
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self.cursor.execute(sql, list(item.values()))
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self.conn.commit()
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except mysql.connector.Error as e:
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spider.log(f"Error when inserting item: {e}")
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self.conn.rollback()
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raise DropItem(f"Error when inserting item: {e}")
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return item
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