MySQL storing TIMESTAMP with milliseconds - mysql

Question

I need to create a database to store some logs which can occurs once per millisecond.
I've created the following table:
CREATE TABLE `log` (
`DataEvento` timestamp(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
`CodiceEvento` int(11) NOT NULL,
`IdApplicativo` int(11) NOT NULL,
PRIMARY KEY (`DataEvento`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;
And a stored procedure:
CREATE DEFINER=`root`#`localhost` PROCEDURE `ScriviEvento`(IN evt_id INT, IN app_id INT, IN evt_descr TEXT)
BEGIN
DECLARE timestamp_now TIMESTAMP(3) DEFAULT NOW(3);
INSERT INTO log (DataEvento, CodiceEvento, IdApplicativo) VALUES (timestamp_now, evt_id, app_id);
IF (LENGTH(evt_descr) > 0) THEN
INSERT INTO descrizionelog (DataEvento, DescrizioneEvento) VALUES (timestamp_now, evt_descr);
END IF;
END
Inserting manually some entries I get the correct timestamp with milliseconds but if I create a thread
with a Sleep(1) I got duplicate key error, same happens if I press execute button fast in workbench with
CALL(1, 0, '');
Is there a workaround to this (excluding using an auto-increment id), or am I doing something wrong?

Answer 1

You are doing something wrong by assuming that the timestamp is going to be unique for log records. That really doesn't make sense.
I'm not sure why you are opposed to an auto-increment solution. This would be the right approach:
CREATE TABLE `log` (
LogId int auto_increment primary key,
`DataEvento` timestamp(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
`CodiceEvento` int NOT NULL,
`IdApplicativo` int NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;