2022年 11月 9日

python 事务操作_Python实现完整的事务操作示例

本文实例讲述了Python事务操作实现方法。分享给大家供大家参考,具体如下:

#coding=utf-8

import sys

import MySQLdb

class TransferMoney(object):

def __init__(self,conn):

self.conn = conn

#检查账户是否合法

def check_acct_avaiable(self,acctid):

cursor = self.conn.cursor()

try:

sql = “select * from account where acctid=%s” % acctid

cursor.execute(sql)

print “check account:” + sql

rs = cursor.fetchall()

if len(rs) != 1:

raise Exception(“account %s illega” % acctid)

finally:

cursor.close()

#检查是否有足够的钱

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(“account %s not enough money” % acctid)

finally:

cursor.close()

#账户减钱

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(“reduce money fail %s” % acctid)

finally:

cursor.close()

#账户加钱

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(“add money fail %s” % acctid)

finally:

cursor.close()

#主执行语句

def transfer(self,source_acctid,target_acctid,money):

try:

self.check_acct_avaiable(source_acctid)

self.check_acct_avaiable(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

if __name__ == “__main__”:

source_acctid = sys.argv[1]

target_acctid = sys.argv[2]

money = sys.argv[3]

conn = MySQLdb.Connect(host = ‘127.0.0.1’,port=3306,user=’root’,passwd=”,db=’test’,charset=’utf8′)

tr_money = TransferMoney(conn)

try:

tr_money.transfer(source_acctid,target_acctid,money)

except Exception as e:

print “Happen:” + str(e)

finally:

conn.close()

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希望本文所述对大家Python程序设计有所帮助。