SQL语句参数化__封装

封装SQL语句参数化（以下代码写为sqlcanshuhua.py文件）

# encoding=utf-8from pymysql import *class MysqlHelper:    def __init__(self,user,passwd,db,host='localhost',port=3306,charset='utf8'):  #注意这里有默认值的变量一定要放在没有默认值变量的后面        self.host = host        self.port = port        self.user = user        self.passwd = passwd        self.db = db        self.charset = charset    def open(self):        self.conn=connect(host=self.host,port=self.port,db=self.db,                     user=self.user,passwd=self.passwd ,charset=self.charset)        self.cursor=self.conn.cursor()    def close(self):        self.cursor.close()        self.conn.close()    def cud(self,sql,params):  #增加、修改、删除        try:            self.open()            self.cursor.execute(sql,params)            self.conn.commit()            print('ok')            self.close()        except Exception as e:            print(e)    def cha_all(self,sql,params=()):  #查询获取多个值        try:            self.open()            self.cursor.execute(sql,params)            result = self.cursor.fetchall()            self.close()            return result        except Exception as e:            print(e.message)

• 调用cud方法：

from sqlcanshuhua import *xtz = MysqlHelper(user='root',passwd='123',db='test')name=input('请输入学生姓名：')gender = input('请输入学生性别：')params = [name,gender]sql = 'INSERT students(sname,gender) VALUES(%s,%s)'xtz.cud(sql,params) #这里不用再单独调用open和close，因为他们已经封装到cud函数里面了

• 运行：

• 调用cha_all方法：

from sqlcanshuhua import *xtz = MysqlHelper(user='root',passwd='123',db='test')sql = 'SELECT * FROM students'xtz.cha_all(sql)

• 运行：