使用Yii ActiveRecord在大型表中进行遍历-“内存不足"错误 [英] Foreach through a large table using Yii ActiveRecord - "out of memory" errors

问题描述

我有一个有关Yii Framework的网站，我想搜索一个表以查找匹配的单词.

I have a website on Yii Framework and I want to search a table for matching words.

我一直得到"out of memory"(这是一张大桌子).

I keep getting "out of memory" (it is a large table).

我尝试使用此代码，但是它会继续加载页面

I try this code but it keeps loading the page

$dataProvider = new CActiveDataProvider('Data');
$iterator = new CDataProviderIterator($dataProvider);
foreach($iterator as $data) {
    echo $data->name."\n";
}

因此，我尝试使用此代码，但始终将结果限制为10:

So I try this code but it keeps limiting the result to 10:

$dataProvider = new CActiveDataProvider('Data');
$iterator = new CDataProviderIterator($dataProvider);
foreach($dataProvider as $data) {
    echo $data->name."\n";
}

如果执行此操作，则会收到内存不足"消息:

and if I do this I get the "out of memory" message:

$dataProvider = new CActiveDataProvider('Data' array(
    'criteria'=>array(
        'order'=>'id DESC',
    ),
    'pagination' => false
));

foreach($dataProvider as $data) {
    echo $data->name."\n";
}

推荐答案

对大型数据集使用CActiveDataProvider是不明智的.特别是如果您只想对它们执行后台任务. 建议使用直接SQL并从那里开始.

It is unwise to use CActiveDataProvider for big datasets. Especially if you only want to perform background tasks on them. It would be advised to use direct SQL and go from there.

基于对CreatoR答案的评论，您正在尝试在一个大表中查找大量的事件.例如:

Based on the comments on CreatoR's answer, you are trying to find a number of occurences in a big table. As an example:

$connection=Yii::app()->db;
$sql = "SELECT id FROM data WHERE field1 LIKE '%someValue%' OR field2 LIKE '%someValue%' OR field3 LIKE '%someValue%'";
$command=$connection->createCommand($sql);
$numberOfRestuls=$command->execute();
//if you also want to display the results :
$ids=$command->queryAll();
$criteria=new CDbCriteria;
$criteria->addInCondition('id',$ids,'OR');
$dataProvider = new CActiveDataProvider('Data', $criteria);
//etc

这篇关于使用Yii ActiveRecord在大型表中进行遍历-“内存不足"错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！