python-mysql实现简单功能

记录我在慕课上学的一段代码

# coding=utf-8

import sys
import MySQLdb


class TransferMoney(object):
    def __init__(self, conn):
        self.conn = conn

    def check_acct_available(self, acctid):
        cursor = self.conn.cursor()
        try:
            sql = "select * from account where acctid=%s" % acctid
            cursor.execute(sql)
            print "check_acct_available:" + sql
            rs = cursor.fetchall()
            if len(rs) != 1:
                raise Exception("账户%s不存在" % acctid)
        finally:
            cursor.close()

    def has_enough_money(self, acctid, money):
        cursor = self.conn.cursor()
        try:
            sql = "select * from account where acctid=%s and money>%s" % (acctid,money)
            cursor.execute(sql)
            print "has_enough_money:" + sql
            rs = cursor.fetchall()
            if len(rs) != 1:
                raise Exception("账户%s没有足够的钱" % acctid)
        finally:
            cursor.close()

    def reduce_money(self, acctid, money):
        cursor = self.conn.cursor()
        try:
            sql = "update account set money=money-%s where acctid=%s" % (money,acctid)
            cursor.execute(sql)
            print "reduce_money:" + sql
            if cursor.rowcount != 1:
                raise Exception("账户%s减款失败" % acctid)
        finally:
            cursor.close()

    def add_money(self, acctid, money):
        cursor = self.conn.cursor()
        try:
            sql = "update account set money=money+%s where acctid=%s" % (money,acctid)
            cursor.execute(sql)
            print "add_money:" + sql
            if cursor.rowcount != 1:
                raise Exception("账户%s加款失败" % acctid)
        finally:
            cursor.close()


    def transfer(self, source_acctid, target_acctid, money):
        try:
            self.check_acct_available(source_acctid)
            self.check_acct_available(target_acctid)
            self.has_enough_money(source_acctid, money)
            self.reduce_money(source_acctid, money)
            self.add_money(target_acctid, money)
            self.conn.commit()
        except Exception as e:
            self.conn.rollback()
            raise e

#  先写程序的入口
if __name__ == "__main__":
    source_acctid = sys.argv[1]
    target_acctid = sys.argv[2]
    money = sys.argv[3]
#  连接到数据库
    conn = MySQLdb.connect(host="localhost",port=3306,user="root",passwd="数据库密码",db="数据库名",charset="utf8")
    tr_money = TransferMoney(conn)

    try:
        tr_money.transfer(source_acctid, target_acctid, money)
    except Exception as e:
        print "出现问题" + str(e)
    finally:
        conn.close()

当然要先在自己的数据库中创建一个account表，然后在表中插入相应数据