pycharm操作pymysq(银行转账）

银行转账案例

import sys
import pymysql

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

    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:
            raise e

    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("账号%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("账号%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("账号%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("reduce_money: " + sql)
            if cursor.rowcount != 1:
                raise Exception("账号%s加款失败" % acctid)
        finally:
            cursor.close()


if __name__ ==  '__main__':
    source_acctid = sys.argv[1]
    target_acctid = sys.argv[2]
    money = sys.argv[3]

    conn = pymysql.connect("localhost", "root", "1995", "test")
    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()

转账前

转账后