Python学习笔记 - MySql的使用

内容导读

互联网集市收集整理的这篇技术教程文章主要介绍了Python学习笔记 - MySql的使用，小编现在分享给大家，供广大互联网技能从业者学习和参考。文章包含3899字，纯文字阅读大概需要6分钟。

内容图文

三、范例

MySql脚本

-- ----------------------------
-- Table structure for account
-- ----------------------------
DROP TABLE IF EXISTS `account`;
CREATE TABLE `account`  (
  `acctid` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `money` decimal(50, 0) NULL DEFAULT NULL
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of account
-- ----------------------------
INSERT INTO `account` VALUES (‘1‘, ‘张三‘, 50);
INSERT INTO `account` VALUES (‘2‘, ‘李四‘, 150);

Python程序

#   coding:utf8
import sys
import pymysql


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
            print("check_acct_available:" + sql)
            cursor.execute(sql)
            rs = cursor.fetchall()
            if len(rs) != 1:
                raise Exception("帐号%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)
            print("has_enough_money:" + sql)
            cursor.execute(sql)
            rs = cursor.fetchall()
            if len(rs) != 1:
                raise Exception("帐号%s没有足够的金额" % 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)
            print("reduce_money:" + sql)
            cursor.execute(sql)
            if cursor.rowcount != 1:
                raise Exception("帐号%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)
            print("add_money:" + sql)
            cursor.execute(sql)
            if cursor.rowcount != 1:
                raise Exception("帐号%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()
            print("transfer出现异常：" + str(e))
            raise e


def main():
    source_acctid = sys.argv[1]
    print("转出帐号=" + source_acctid)
    target_acctid = sys.argv[2]
    print("转入帐号=" + target_acctid)
    money = sys.argv[3]
    print("金额=" + money)

    # 连接数据库
    conn = pymysql.Connect(
        host=‘localhost‘,
        port=3306,
        user=‘root‘,
        passwd=‘root‘,
        db=‘OtkDb‘,
        charset=‘utf8‘)

    tr_money = TransferMoney(conn)

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


if __name__ == ‘__main__‘:
    main()

 四、运行效果

PS H:\web\Python> & python h:\web\Python\01.MySql\db.py 1 2 50
转出帐号=1
转入帐号=2
金额=50
check_acct_available:select * from account where acctid=‘1‘
check_acct_available:select * from account where acctid=‘2‘
has_enough_money:select * from account where acctid=‘1‘ and money>50
reduce_money:update account set money=money-50 where acctid=‘1‘
add_money:update account set money=money+50 where acctid=‘2‘


PS H:\web\Python> & python h:\web\Python\01.MySql\db.py 1 2 50
转出帐号=1
转入帐号=2
金额=50
check_acct_available:select * from account where acctid=‘1‘
check_acct_available:select * from account where acctid=‘2‘
has_enough_money:select * from account where acctid=‘1‘ and money>50
transfer出现异常：帐号1没有足够的金额
main出现异常：帐号1没有足够的金额

参考：

http://www.cnblogs.com/woider/p/5926744.html

Python学习笔记 - MySql的使用

标签：cursor   参考   python程序   密码   执行   支持   影响   ini   close   

本文系统来源：https://www.cnblogs.com/chuancheng/p/8456918.html

内容总结

以上是互联网集市为您收集整理的Python学习笔记 - MySql的使用全部内容，希望文章能够帮你解决Python学习笔记 - MySql的使用所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错，欢迎将互联网集市网站推荐给程序员好友。

内容备注

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 gblab@vip.qq.com 举报，一经查实，本站将立刻删除。

内容手机端