Doctrine keeps updating DATETIME on update CURRENT_TIMESTAMP - symfony

Question

I have parent entity class:
namespace App\Model\Entities;
use Doctrine\ORM\Mapping as ORM;
/**
* #ORM\MappedSuperclass
*/
abstract class ParentEntity
{
/**
* #var int|null
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue
*/
protected $id;
/**
* #ORM\Column(type="datetime", columnDefinition="DATETIME on update CURRENT_TIMESTAMP")
*/
protected $modifiedOn;
}
and everytime I run php bin/console o:s:u --dump-sql or --force the console prints out that X queries will be executed and every query is for modified_on column.
ALTER TABLE contact CHANGE modified_on modified_on DATETIME on update CURRENT_TIMESTAMP;
ALTER TABLE about_us CHANGE modified_on modified_on DATETIME on update CURRENT_TIMESTAMP;
ALTER TABLE image CHANGE modified_on modified_on DATETIME on update CURRENT_TIMESTAMP;
...
In MySQL database everything is setup correctly:
CREATE TABLE `about_us` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`modified_on` datetime DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
So my question is why is this happening? Did I miss some configuration/annotation for Doctrine? Or do you have to specify this attribute in some other way?

Answer 1

You are probably after Lifecycle Callbacks. if so this is the way to go:
namespace App\Model\Entities;
use Doctrine\ORM\Mapping as ORM;
/**
* #ORM\MappedSuperclass
* #ORM\HasLifecycleCallbacks
*/
abstract class ParentEntity
{
/**
* #var int|null
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue
*/
protected $id;
/**
* #ORM\Column(type="datetime")
*/
protected $modifiedOn;
/**
* #ORM\PreUpdate
*/
public function setModifiedOn()
{
$this->modifiedOn = new \DateTime();
}
}