PDBC（连接数据库）

import pymysql
class Cpymysql():
    def __init__(self):
        self.conn=pymysql.connect(host='127.0.0.1',port=3306,user='root',password='1111',database='atm_woniu')
        self.cur=self.conn.cursor()

    # def chage_db(sql):
    def change_db(self,sql):
        # 执行sql语句
        self.cur.execute(sql)
        # 提交事务
        self.conn.commit()


    # 查询
    def query_db(self,sql,mod):
        # 执行sql语句
        self.cur.execute(sql)
        # 获取数据
        if mod == 'all':
            result01 = self.cur.fetchall()
        elif mod == 'one':
            result01 = self.cur.fetchone()
        elif mod == 'many':
            result01 = self.cur.fetchmany()
        return result01

    # 断开连接
    def __del__(self):
        self.cur.close()
        self.conn.close()

name="admin"
mysql = "SELECT password FROM user where username='%s';" %name
cp=Cpymysql()
x=cp.query_db(mysql,'one')
print(x)