一段代码逻辑问题 [ 2.0 版本 ]

public function search($params)
{
    $query = $this->finder->getUserQuery();

    $dataProvider = new ActiveDataProvider([
        'query' => $query,
    ]);

    if (!($this->load($params) && $this->validate())) {
        return $dataProvider;
    }
    
    if ($this->created_at !== null) {
        $date = strtotime($this->created_at);
        $query->andFilterWhere(['between', 'created_at', $date, $date + 3600 * 24]);
    }
    
    $query->andFilterWhere(['like', 'username', $this->username])
        ->andFilterWhere(['like', 'email', $this->email])
        ->andFilterWhere(['registration_ip' => $this->registration_ip]);

    return $dataProvider;
}