在MySQL中创建表时出错

Question

CREATE DATABASE vehicle_system;

USE vehicle_system;

USE vehicle_system; CREATE TABLE IF NOT EXISTS `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) DEFAULT NULL,
  `email` varchar(255) NOT NULL, 
  `password_hash` text NOT NULL, 
  `api_key` varchar(32) NOT NULL, 
  `phone` varchar(14) NOT NULL, 
  `status` int(1) NOT NULL DEFAULT '1', 
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, 
  `updated_at` timestamp NOT NULL, 
  PRIMARY KEY (`id`), 
  UNIQUE KEY `email` (`email`), 
  UNIQUE KEY `phone` (`phone`)
);

CREATE TABLE IF NOT EXISTS `vehicle_model` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) DEFAULT NULL,
  `manufacturer_id` int(11) NOT NULL,
  `manufacturer_name` varchar(250) NOT NULL,
  `model` varchar(32) NOT NULL,
  `model_no` varchar(32) NOT NULL,
  `type` varchar(32) NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `manufacturer_id` (`manufacturer_id`)
);

CREATE TABLE IF NOT EXISTS `user_vehicles` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) DEFAULT NULL,
  `user_id` int(11) NOT NULL,
  `manufacturer_id` int(11) NOT NULL,
  `vehicle_no` varchar(32) NOT NULL,
  `rc_no` text,
  `engine_type` varchar(32),
  `year` int(4),
  `insurance_exp_date` timestamp,
  `pollution_exp_date` timestamp,
  `rc_renew_date` timestamp,
  `insurance_company` varchar(32),
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `vehicle_no` (`vehicle_no`),
  KEY `user_id` (`user_id`),
  KEY `manufacturer_id` (`manufacturer_id`)
);

While executing above query I get

#1293 - Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause

But I do not see two default time stamp in the query, Can any one point out what could be the possible error. Is it because current time stamp is present in the users table ? If so how to get rid of this ?

Answer 1

I think the problem is that you do not have a default for all the fields of type timestamp.

Running your query I got the following error:

Error Code: 1067. Invalid default value for 'updated_at'

Then I got:

Error Code: 1067. Invalid default value for 'pollution_exp_date'

Everything works fine when all the timestamp field have a default value:

CREATE DATABASE vehicle_system;

USE vehicle_system;

USE vehicle_system; CREATE TABLE IF NOT EXISTS `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) DEFAULT NULL,
  `email` varchar(255) NOT NULL, 
  `password_hash` text NOT NULL, 
  `api_key` varchar(32) NOT NULL, 
  `phone` varchar(14) NOT NULL, 
  `status` int(1) NOT NULL DEFAULT '1', 
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, 
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, 
  PRIMARY KEY (`id`), 
  UNIQUE KEY `email` (`email`), 
  UNIQUE KEY `phone` (`phone`)
);

CREATE TABLE IF NOT EXISTS `vehicle_model` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) DEFAULT NULL,
  `manufacturer_id` int(11) NOT NULL,
  `manufacturer_name` varchar(250) NOT NULL,
  `model` varchar(32) NOT NULL,
  `model_no` varchar(32) NOT NULL,
 `type` varchar(32) NOT NULL,
 `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
 `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `manufacturer_id` (`manufacturer_id`)
);

CREATE TABLE IF NOT EXISTS `user_vehicles` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) DEFAULT NULL,
  `user_id` int(11) NOT NULL,
  `manufacturer_id` int(11) NOT NULL,
  `vehicle_no` varchar(32) NOT NULL,
  `rc_no` text,
  `engine_type` varchar(32),
  `year` int(4),
  `insurance_exp_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `pollution_exp_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `rc_renew_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `insurance_company` varchar(32),
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `vehicle_no` (`vehicle_no`),
  KEY `user_id` (`user_id`),
  KEY `manufacturer_id` (`manufacturer_id`)
);

This is on MySql 5.7.10.

There is an interesting discussion on this here:

https://bugs.mysql.com/bug.php?id=41137

Creation of timestamp fields is different from any other!

Practically up to 5.6.6 you do not have to declare NOT NULL as by definition that field is NOT NULL and with neither DEFAULT nor ON UPDATE clauses, it is the same as DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP.

After 5.6.6 you have to explicit defaults. Look also:

https://dev.mysql.com/doc/refman/5.5/en/timestamp-initialization.html

and

http://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html

Finally, in your case removing NOT NULL is the best approach.

Regards