mysql—python交互

Posted 2021-02-27 三夕

安装pymysql

import pymysql

1.链接数据库 连接对象connection

try:
conn=pymysql.Connect(
host="localhost",
port=3306,
db="er",
user="root",
passwd="password",
charset="utf8"
)
#2.创建游标对象cursor
cur=conn.cursor()

# #增加一条数据  科目表加上爬虫
# insert_sub=‘insert into subjects values(0,"爬虫")‘
# result=cur.execute(insert_sub)

# #修改
# update_sub=‘update subjects set title="物理" where id=3‘
# result = cur.execute(update_sub)

#删除  sub表有外键关联，删不掉，不用管，记住操作就行
# delete_sub=‘delete from subjects where id=4‘
# result=cur.execute(delete_sub)
# print(result)

#fetchall接收所有的结果  只能fetch一次，第二次结果就是None
#一行数据一个元组
cur.execute(‘select * from subjects‘)
res=cur.fetchall()
print(res)      #((1, ‘语文‘), (2, ‘数学‘), (3, ‘物理‘), (4, ‘科学‘), (6, ‘爬虫‘))
#fetchone：每次一行数据

#提交事务
conn.commit()
#关闭游标
cur.close()
#关闭链接
conn.close()

except Exception as e:
print(e)