autoincrement attribute is always null after save() - mysql

Question

I have table query with field id which is autoincrement primary key.
Model
class Query extends \yii\db\ActiveRecord
{
public static function tableName()
{
return '{{%query}}';
}
public function rules()
{
return [
[['id', 'created_at'], 'integer'],
[['data'], 'string'],
];
}
}
Application
$q = new Query();
$q->created_at = time();
$q->data = Json::encode($query);
if ($q->save())
echo $q->id == null ? "null" : $q->id;
else
echo "Validation error";
Result is null, though new record with incremented id does occur in database.
Also I see only insert record in db log, but no record to obtain inserted row id.
What's wrong?

Answer 1

as you can see in vendor/yiisoft/yii2/db/ActiveRecord.php
there is already a primaryKey method
public static function primaryKey()
{
return static::getTableSchema()->primaryKey;
}
that return the proper primaryKey for the tableSchema
so you should not redefine this method ..
the method is specifically called primaryKey() not getPrimaryKey() .. this last one is the magic getter .. and return a value for var $primaryKey ..
if no insert is performed could be you have some validation problems .. try (just for debugging) using save(false)