封装（python 版）

封装

• 观察前面的文件发现，除了SQL语句及参数不同，其它语句都是一样的
• 创建MysqlHelper.py文件，定义类

  #encoding=utf8
  import MySQLdb
  
  class MysqlHelper():
      def __init__(self,host,port,db,user,passwd,charset='utf8'):
          self.host=host
          self.port=port
          self.db=db
          self.user=user
          self.passwd=passwd
          self.charset=charset
  
      def connect(self):
          self.conn=MySQLdb.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 get_one(self,sql,params=()):
          result=None
          try:
              self.connect()
              self.cursor.execute(sql, params)
              result = self.cursor.fetchone()
              self.close()
          except Exception, e:
              print e.message
          return result
  
      def get_all(self,sql,params=()):
          list=()
          try:
              self.connect()
              self.cursor.execute(sql,params)
              list=self.cursor.fetchall()
              self.close()
          except Exception,e:
              print e.message
          return list
  
      def insert(self,sql,params=()):
          return self.__edit(sql,params)
  
      def update(self, sql, params=()):
          return self.__edit(sql, params)
  
      def delete(self, sql, params=()):
          return self.__edit(sql, params)
  
      def __edit(self,sql,params):
          count=0
          try:
              self.connect()
              count=self.cursor.execute(sql,params)
              self.conn.commit()
              self.close()
          except Exception,e:
              print e.message
          return count

  添加

  • 创建testInsertWrap.py文件，使用封装好的帮助类完成插入操作

  #encoding=utf8
  from MysqlHelper import *
  
  sql='insert into students(sname,gender) values(%s,%s)'
  sname=raw_input("请输入用户名：")
  gender=raw_input("请输入性别，1为男，0为女")
  params=[sname,bool(gender)]
  
  mysqlHelper=MysqlHelper('localhost',3306,'test1','root','mysql')
  count=mysqlHelper.insert(sql,params)
  if count==1:
      print 'ok'
  else:
      print 'error'
  

  查询一个

  • 创建testGetOneWrap.py文件，使用封装好的帮助类完成查询最新一行数据操作

  #encoding=utf8
  from MysqlHelper import *
  
  sql='select sname,gender from students order by id desc'
  
  helper=MysqlHelper('localhost',3306,'test1','root','mysql')
  one=helper.get_one(sql)
  print one