Yii说它可以自动设置时间戳'created_at': http://www.yiiframework.com/doc-2.0/guide-concept-behaviors.html#using-timestampbehavior
但是，每次创建记录时，时间都是空白的:
$ yii kw/test
1437683634
mysql> select * from ad_group_keyword_network where ad_group_keyword_id = 1;
+---------------------+-
| created_at |
+---------------------+-
| 0000-00-00 00:00:00 |
| 0000-00-00 00:00:00 |
+---------------------+-
public function actionTest() {
$agkn = new AdGroupKeywordNetwork();
$agkn->save();
echo $agkn->created_at;
我尝试了Schema::TYPE_TIMESTAMP，我改变了领域，也尝试了Schema::TYPE_DATETIME。它们都在保存后的字段中返回一个整数时间戳，但在数据库中时间都是0。
public function behaviors()
{
return [
[
'class' => TimestampBehavior::className(),
'attributes' => [
ActiveRecord::EVENT_BEFORE_INSERT => ['created_at'],
ActiveRecord::EVENT_BEFORE_UPDATE => [],
您的created_at必须是INT(11)类型的Yii 2时间戳行为的工作。
根据Marc和Michael的说法，我使用了这个方法，而且很有效。
public function behaviors()
{
return [
[
'class' => TimestampBehavior::className(),
'createdAtAttribute' => 'created_at',
'updatedAtAttribute' => null,
'value' => function(){return date(DATE_ATOM);},
$ yii kw/test
2015-07-23T16:59:17-04:00
...
+---------------------+
| created_at |
+---------------------+
| 2015-07-23 16:59:17 |
$value是将用于生成时间戳的表达式，默认情况下它将使用time()的值，除非您给它分配一个返回时间戳值的匿名函数:
'timestamp' => [
'class' => TimestampBehavior::className(),
'attributes' => [
ActiveRecord::EVENT_BEFORE_INSERT => 'created_at',
ActiveRecord::EVENT_BEFORE_UPDATE => 'updated_at',
],
'value' => function() { return date('U'); },
],
或一个表示db表达式的yii'db'Expression对象:
'timestamp' => [
'class' => TimestampBehavior::className(),
'attributes' => [
ActiveRecord::EVENT_BEFORE_INSERT => 'created_at',
ActiveRecord::EVENT_BEFORE_UPDATE => 'updated_at',
],
'value' => new 'yii'db'Expression('NOW()'), // MySql exp
],