一、安装MySql模块
Python2.X
pip install MySQLdb
Python3.X
pip install pymysql
二、数据库连接接口
由于Python统一了数据库连接的接口，所以 pymysql 和 MySQLdb 在使用方式上是类似的：
pymysql.Connect()参数说明host(str): MySQL服务器地址port(int): MySQL服务器端口号user(str): 用户名passwd(str): 密码db(str): 数据库名称charset(str): 连接编码connection对象支持的方法cursor() 使用该连接创建并返回游标commit() 提交当前事务rollback() 回滚当前事务close() 关闭连接cursor对象支持的方法execute(op) 执行一个数据库的查询命令fetchone() 取得结果集的下一行fetchmany(size) 获取结果集的下几行fetchall() 获取结果集中的所有行rowcount() 返回数据条数或影响行数close() 关闭游标对象
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:utf8import sysimport pymysqlclass 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 edef 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=50check_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>50reduce_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=50check_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>50transfer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