MySQL或Yii2 ActiveRecord

Question

I have table with test_id and created_at

Column "created_at" has different values. I want to executed SQL query, where split by column "created_at". Where

This structure

I want to get this structure of array:

$all = array('created_at'=>'somevalues', 'test'=>array()); 

Answer 1

It depends how many values we are talking about. If you have 100 different created_at values your solution will run 100+1 queries. So you will put a lot of pressure on the server. If you have a lot of created_at values a better solution would be to just get the data, order it by created_at and go through the results and group them manually. I believe this will be a lot, lot faster than what you are trying to do. Something like

$model = Model::find()->orderBy(['created_at' => SORT_ASC])->all();
foreach($model as $item) {
     $data[$item->created_at]['results'][] = $item;
     // $data[$item->created_at]['created_at'] = $item->created_at; if you really need to 
}

In the end you will end up with something almost exactly how you wanted it.