python - MySQL 连接器/Python 存储过程插入未提交

Question

我正在编写一个 python 脚本来监控 Raspberry Pi 的几个 1wire 传感器并将结果存储在 MySQL 数据库中。使用 MySQL 连接器/Python 库，我可以成功连接到数据库，并运行查询，但是事务似乎没有完全提交。我知道查询运行成功，因为输出参数设置为新的自动递增 ID。

CREATE TABLE `lamp`.`sensors` (
 `SensorID` int(11) unsigned NOT NULL AUTO_INCREMENT,
 `SensorSerial` char(15) NOT NULL,
 `SensorFamily` tinyint(4) NOT NULL,
 PRIMARY KEY (`SensorID`),
 UNIQUE KEY `SensorID_UNIQUE` (`SensorID`),
 UNIQUE KEY `SensorSerial_UNIQUE` (`SensorSerial`)
)

CREATE PROCEDURE `lamp`.`AddSensor` (sensorSerial char(15),
                         sensorFamily tinyint, out returnValue int)
BEGIN
 INSERT INTO sensors (SensorSerial,SensorFamily) VALUES (sensorSerial,sensorFamily);
 SET returnValue=LAST_INSERT_ID();
END

但是，当我尝试查询表时(从传感器中选择 *)，我得到 0 个结果。如果我从 MySQL Workbench 或 .Net 应用程序运行该过程，一切都会按预期进行。这意味着我在连接器/Python 方面遗漏了一些东西，但我不知道是什么。我非常困惑，因为自动增量值确实增加了，但没有添加任何记录。也没有报错

 def Test(self):
    #this line works fine
    #self.RunProcedure("INSERT INTO sensors (SensorSerial,SensorFamily) VALUES ('{0}',{1})".format(self.ID,self.Family),False,())
    #this line does not?
    args=self.RunProcedure('AddSensor',True,(self.ID,self.Family,-1))
    if args[2]>=1:
        logging.debug("Successfully added sensor data '{1}' for sensor '{0}' to the database".format(self.ID,value))
        return True
    else:
        logging.critical("Failed to add Data to Database for unknown reason. SensorID: {0} Type: {1} Data:{2}".format(self.ID,self.Family,value))

def RunProcedure(self,proc,isStored,args):
    try:
        logging.debug("Attempting to connect to database.")
        connection=mysql.connector.connect(user='root',password='1q2w3e4r',host='localhost',database='LAMP')
    except mysql.connector.Error as e:
        logging.exception("Failed to connect to mysql database.\r\n {0}".format(e))
    else:
        logging.debug("Successfully connected to database.")
        try:
            cursor=connection.cursor()
            if isStored:
                args = cursor.callproc(proc,args)
                return args
            else:
                cursor.execute(proc,args)
            #these do not seem to solve the issue.
            #cursor.execute("Commit;")
            #connection.commit()
        except mysql.connector.Error as e:
            logging.exception("Exception while running the command '{0}' with the args of '{1}' exception is {2}".format(proc,args,e))
        finally:
            logging.debug("Closing connection to database")
            cursor.close()
            connection.close()

从到日志的输出如下所示；

2013-06-09 13:21:25,662 Attempting to connect to database.
2013-06-09 13:21:25,704 Successfully connected to database.
2013-06-09 13:21:25,720 Closing connection to database
2013-06-09 13:21:25,723 Successfully added sensor data '22.25' for sensor '10.85FDA8020800' to the database

**编辑

不知道为什么，但是将 autocommit=True 添加到 connection.open 参数似乎已经解决了这个问题。既然提交有问题，为什么 connection.commit() 或 cursor.execute('commit;') 没有更正问题？

Answer 1

问题其实出在你的代码中:

    ..
    try:
        cursor=connection.cursor()
        if isStored:
            args = cursor.callproc(proc,args)
            return args
        else:
            cursor.execute(proc,args)
        connection.commit()
    except mysql.connector.Error as e:
    ..

如果您正在使用存储例程，您将立即返回，因此永远不会调用 commit()。