Question

如何迭代dataprovider对象？我想访问返回的每行的'name'字段并构建一个列表。你能帮忙吗？

表格/模型的表格结构categories

CREATE TABLE IF NOT EXISTS `categories` (
  `idCategory` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(64) NOT NULL,
  PRIMARY KEY (`idCategory`) USING BTREE
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=55 ;

* 我的控制器类别中的功能 *

    $names = array();
    public function returnCategoryNames()
{
    $dataProvider= new CActiveDataProvider('Categories');
    $dataProvider->setPagination(false);
    $count = $dataProvider->totalItemCount();

    for($i = 0; $i < $count; $i++){

             // this is where I am lost...
             $myname = $dataProvider->data[$i]->name;
             array_push($names, $myname);

    }   

       return $names;

}

Answer 1

试试这个：

public function returnCategoryNames()
{
  $dataProvider= new CActiveDataProvider('Categories');
  $dataProvider->setPagination(false);
  //$count = $dataProvider->totalItemCount();
  $names = array();
  foreach($dataProvider->getData() as $record) {
    $names[] = $record->name;
  }
  return array_unique($names);
}

但是，您不需要使用数据提供程序，而只需使用模型

foreach(Categories::model()->findAll() as $record) {

Answer 2

如果您需要大量数据收集并且担心内存使用，请执行以下操作：

$dataProvider = new CActiveDataProvider('Categories');
$iterator = new CDataProviderIterator($dataProvider);
foreach($iterator as $category) {
   print_r($category);
}

CDataProviderIterator允许对大型数据集进行迭代，而无需将整个集合保存在内存中。

一些性能测试

Test                        Time (seconds)          Memory (bytes)
CDbDataReader               4.9158580303192         28339952
CActiveRecord::findAll()    5.8891110420227         321388376
CDataProviderIterator       6.101970911026          31170504

Answer 3

在Yii2中，这也发生了变化：

    $searchModel = new ModelSearch();
    $dataProvider = $searchModel->search(Yii::$app->request->queryParams);

    foreach($dataProvider->getModels() as $record) {
        echo $record->id . '<br>';
    }

    exit();

参考：getModels()

Answer 4

使用@ ben-rowe的解决方案，您可以立即查询所有行。你可能有内存问题。

使用以下解决方案，您将从十到十（默认CPagination.pageSize值）获取类别：

        $dataProvider = new CActiveDataProvider('Categories', array(
            'pagination' => array(
                'validateCurrentPage' => false
            ),
        ));
        $pagination = $dataProvider->pagination;
        while ($categories = $dataProvider->getData(true)){
            foreach ($categories as $category) {
                //...
            }
            $pagination->currentPage++;
        }

如何迭代Yii CActiveDataProvider对象？

4 个答案: