我编写代码从eBay.com中删除汽车信息（标题，制造，型号，传输，年份，价格）数据并保存在mysql中，我希望如果所有行的（标题，制造，型号，。。。）条目的都与另一行相似，那么避免将此数据插入mysql，*只有当所有行的条目都相似时（因为某些标题是simialr或某些型号或。。。）
代码:
import requests
from bs4 import BeautifulSoup
import re
import mysql.connector
conn = mysql.connector.connect(user='root', password='******',
host='127.0.0.1', database='web_scraping')
cursor = conn.cursor()
url = 'https://www.ebay.com/b/Cars-Trucks/6001?_ fsrp=0&_sacat=6001&LH_BIN=1&LH_ItemCondition=3000%7C1000%7C2500&rt=nc&_stpos=95125&Model%2520Year=2020%7C2019%7C2018%7C2017%7C2016%7C2015'
res = requests.get(url)
soup = BeautifulSoup(res.text, 'html.parser')
ebay_cars = soup.find_all('li', class_='s-item')
for car_info in ebay_cars:
title_div = car_info.find('div', class_='s-item__wrapper clearfix')
title_sub_div = title_div.find('div', class_='s-item__info clearfix')
title_p = title_sub_div.find('span', class_='s-item__price')
title_tag = title_sub_div.find('a', class_='s-item__link')
title_maker = title_sub_div.find('span', class_='s-item__dynamic s-
item__dynamicAttributes1')
title_model = title_sub_div.find('span', class_='s-item__dynamic s-
item__dynamicAttributes2')
title_trans = title_sub_div.find('span', class_='s-item__dynamic s-
item__dynamicAttributes3')
name_of_car = re.sub(r'\d{4}', '', title_tag.text)
maker_of_car = re.sub(r'Make: ','', title_maker.text)
model_of_car = re.sub(r'Model: ', '', title_model.text)
try:
if title_trans.text.startswith(r'Transmission: '):
trans_of_car = re.sub(r'Transmission: ', '', title_trans.text)
else:
trans_of_car = ''
except AttributeError:
trans_of_car = ''
year_of_car = re.findall(r'\d{4}', title_tag.text)
year_of_car = ''.join(str(x) for x in year_of_car)
price_of_car = title_p.text
print(name_of_car ,trans_of_car )
sql = 'INSERT INTO car_info(Title, Maker, Model, Transmission, Year, Price)
VALUES (%s, %s, %s, %s, %s, %s)'
cursor.execute(sql , (name_of_car, maker_of_car, model_of_car, trans_of_car,
year_of_car, price_of_car))
conn.commit()
conn.close()
一个选项使用不存在:
insert into car_info (title, maker, model, transmission, year, price)
select v.*
from (select %s title, %s maker, %s model, %s transmission, %s year, %s price) v
where not exists (
select 1
from car_info c
where
(c.title, c.maker, c.model, c.transmission, c.year, c.price)
= (v.title, v.maker, v.model, v.transmission, v.year, v.price)
);
但是在表的所有列上创建唯一键会更简单，如:
create unique index idx_car_info_uniq
on car_info(title, maker, model, transmission, year, price);
这可以防止任何进程在表中插入重复项。 您可以优雅地忽略本来会用on duplicate key语法引发的错误:
insert into car_info (title, maker, model, transmission, year, price)
values (%s, %s, %s, %s, %s, %s)
on duplicate key update title = values(title);
您可以将此查询的结果保存到一个变量中
SELECT COUNT(*) FROM car_info WHERE Title = <titleValue>, Maker = <makerValue>, Model = <modelValue>, Transmission = <transmisionValue>, Year = <yearValue>, Price = <priceValue>
然后，如果变量的值为
这只是一种方法。
将主键声明为表中的所有列。 见:https://www.mysqltutorial.org/mysql-primary-key/
