我正在对一组 25,000 结果运行下面的代码.我需要优化它,因为我达到了内存限制.
I'm running the code below over a set of 25,000 results. I need to optimize it because i'm hitting the memory limit.
$oldproducts = Oldproduct::model()->findAll(); /*(here i have 25,000 results)*/
foreach($oldproducts as $oldproduct) :
$criteria = new CDbCriteria;
$criteria->compare('`someid`', $oldproduct->someid);
$finds = Newproduct::model()->findAll($criteria);
if (empty($finds)) {
$new = new Newproduct;
$new->someid = $oldproduct->someid;
$new->save();
} else {
foreach($finds as $find) :
if ($find->price != $oldproduct->price) {
$find->attributes=array('price' => $oldproduct->price);
$find->save();
}
endforeach;
}
endforeach;
代码通过someid比较两个表的行.如果发现巧合,它会更新 price 列,否则会创建一个新记录.
Code compares rows of two tables by someid. If it find coincidence it updates price column, if not creates a new record.
使用 CDataProviderIterator
其中:
Use CDataProviderIterator
which:
... 允许对大型数据集进行迭代,而无需将整个数据集保存在内存中.
... allows iteration over large data sets without holding the entire set in memory.
您首先必须将 CDataProvider
实例传递给它:
You first have to pass a CDataProvider
instance to it:
$dataProvider = new CActiveDataProvider("Oldproduct");
$iterator = new CDataProviderIterator($dataProvider);
foreach($iterator as $item) {
// do stuff
}
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