1.连接的基本语法如下：

import pymysql

#创建连接
conn = pymysql.Connect(host="127.0.0.1", port=3306, user="root", passwd="123456",db="test")
# 创建游标
cursor = conn.cursor()

#SQL语句增
sql1 = "insert into user(name) values ('大猪')"
#SQL语句查
sql2 = "select * from user"
#SQL语句改
sql3 = "update user set name = '大大猪' where id = 3"
#SQL语句删
sql4 = "delete from user where id = 3"

# 读取数据
number = cursor.execute(sql4)

print(number)

# 提交事务
conn.commit()

# 关闭游标
cursor.close()

# 关闭连接
conn.close()

2.创建连接模块

# -*- coding: UTF-8 -*-
import pymysql

class Mysql(object):

    def __init__(self):

        #配置mysql数据库信息
        config = {
            'host': '127.0.0.1',
            'port': 3306,
            'user': 'root',
            'passwd': '123456',
            'db': 'demo',
            'charset': 'utf8'
        }

        self.host = config['host']
        self.username = config['user']
        self.password = config['passwd']
        self.port = config['port']
        self.db = config['db']
        self.con = None
        self.cursor = None

        try:
            self.conn = pymysql.connect(**config)
            # 所有的查询，都在连接 con 的一个模块 cursor 上面运行的
            self.cursor = self.conn.cursor(cursor=pymysql.cursors.DictCursor)
        except:
            print("DataBase connect error,please check the db config.")

    def exeCommit(self, sql=''):
        """执行数据库sql语句，针对更新,删除,事务等操作失败时回滚
        """
        try:
            execute = self.cursor.execute(sql)
            self.conn.commit()
			#返回值为受影响的行数
            return  execute
        except pymysql.Error as e:
            self.conn.rollback()
            error = 'MySQL execute failed! ERROR (%s): %s' % (e.args[0], e.args[1])
            print("error:", error)
            return error

    def __del__(self):
        # 关闭cursor对象
        self.cursor.close()
        self.conn.close()