代码演示：
#conding:utf8
import pymysql
import sys class TransferMoney(object):
def __init__(self,conn):
self.conn=conn
def check_acct_available(self,acctid):
cursor = self.conn.cursor()
try:
cursor=self.conn.cursor()
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("账号%s不存在："%acctid)
finally:
cursor.close() def has_enough_money(self,acctid,money):
cursor = self.conn.cursor()
try:
cursor = self.conn.cursor()
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("账号%s没有足够的钱：" % acctid)
finally:
cursor.close()
def reduce_money(self,acctid,money):
cursor = self.conn.cursor()
try:
cursor = self.conn.cursor()
sql = "update account set money = money-%s where acctid=%s" % (money,acctid)
cursor.execute(sql)
print("reduce_money:" + sql)
rs = cursor.fetchall()
if cursor.rowcount!=1:
raise Exception("账号%s减款失败：" % acctid)
finally:
cursor.close() def add_money(self,acctid,money):
cursor = self.conn.cursor()
try:
cursor = self.conn.cursor()
sql = "update account set money = money+%s where acctid=%s" % (money, acctid)
cursor.execute(sql)
print("add_money:" + sql)
rs = cursor.fetchall()
if cursor.rowcount != 1:
raise Exception("账号%s加款失败：" % acctid)
finally:
cursor.close() def transfer(self,source_acctid,target_acctid,money):
'''检查付款人和收款人账号是否存在，检查付款人是否有足够的钱'''
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 if __name__=="__main__":
'''付款人账号id,收款人账号id,转账金额'''
source_acctid=sys.argv[1]
target_acctid=sys.argv[2]
money=sys.argv[3]
conn=pymysql.connect(
host='192.168.199.249',
port=3306,
user='root',
passwd='',
db='imooc',
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()