用python连接mysql，实现一个银行转账的小功能
#coding=utf-8
import pymysql
import sys
class TransferMoney:
def __init__(self,conn):
self.conn = conn
def check_acct_available(self, acctid):
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):
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余额不足" % acctid)
finally:
cursor.close()
def reduce_money(self, acctid, money):
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.rowcount
if rs != 1:
raise Exception("账号%s付款失败" % acctid)
finally:
cursor.close()
def add_money(self, acctid, money):
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.rowcount
if rs != 1:
raise Exception("账号%s收款失败" % 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
if __name__=="__main__":
source_acctid = sys.argv[1]
target_acctid = sys.argv[2]
money = sys.argv[3]
conn = pymysql.connect(
host = '127.0.0.1',
port = 3306,
user = 'root',
passwd = '1234',
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()
