Class yii\behaviors\TimestampBehavior

TimestampBehavior automatically fills the specified attributes with the current timestamp.

To use TimestampBehavior, insert the following code to your ActiveRecord class:

use yii\behaviors\TimestampBehavior;

public function behaviors()
{
    return [
        TimestampBehavior::className(),
    ];
}

By default, TimestampBehavior will fill the created_at and updated_at attributes with the current timestamp when the associated AR object is being inserted; it will fill the updated_at attribute with the timestamp when the AR object is being updated. The timestamp value is obtained by time().

Because attribute values will be set automatically by this behavior, they are usually not user input and should therefore not be validated, i.e. created_at and updated_at should not appear in the rules() method of the model.

For the above implementation to work with MySQL database, please declare the columns(created_at, updated_at) as int(11) for being UNIX timestamp.

If your attribute names are different or you want to use a different way of calculating the timestamp, you may configure the $createdAtAttribute, $updatedAtAttribute and $value properties like the following:

use yii\db\Expression;

public function behaviors()
{
    return [
        [
            'class' => TimestampBehavior::className(),
            'createdAtAttribute' => 'create_time',
            'updatedAtAttribute' => 'update_time',
            'value' => new Expression('NOW()'),
        ],
    ];
}

In case you use an yii\db\Expression object as in the example above, the attribute will not hold the timestamp value, but the Expression object itself after the record has been saved. If you need the value from DB afterwards you should call the refresh() method of the record.

TimestampBehavior also provides a method named touch() that allows you to assign the current timestamp to the specified attribute(s) and save them to the database. For example,

$model->touch('creation_time');