LIMIT is not working in ActiveDataProvider - yii2

Question

I am using following code and the limit doesnt work. But if I see the command than it shows limit in that, but when I pass the query to ActiveDataProvider it fetch all the records:
$data= User::find()->where(['category_id'=> 5])->orderBy(['rand()' => SORT_DESC])->limit(4);
$command = $data->createCommand();
$data2 = $command->queryAll();// This works fine and fetch only 4 data
$dataProvider = new ActiveDataProvider([
'query' => $data,
]); // But this displays all data without limit
What is wrong I am doing here?

Answer 1

Here is what happens when preparing models in yii\data\ActiveDataProvider:
/**
* #inheritdoc
*/
protected function prepareModels()
{
if (!$this->query instanceof QueryInterface) {
throw new InvalidConfigException('The "query" property must be an instance of a class that implements the QueryInterface e.g. yii\db\Query or its subclasses.');
}
$query = clone $this->query;
if (($pagination = $this->getPagination()) !== false) {
$pagination->totalCount = $this->getTotalCount();
$query->limit($pagination->getLimit())->offset($pagination->getOffset());
}
if (($sort = $this->getSort()) !== false) {
$query->addOrderBy($sort->getOrders());
}
return $query->all($this->db);
}
We're interested in this part:
if (($pagination = $this->getPagination()) !== false) {
$pagination->totalCount = $this->getTotalCount();
$query->limit($pagination->getLimit())->offset($pagination->getOffset());
}
So as you can see if pagination is not false, limit is managed automatically.
You can just set pagination to false and then manual setting of limit will work:
$dataProvider = new ActiveDataProvider([
'query' => $query,
'pagination' => false,
]);

Answer 2

You can use Limit in the ActiveDataProvider and keep Pagination like so:-
$dataProvider = new ActiveDataProvider([
'query' => $query,
'pagination' => [
'pageSize' => 50,
],
]);
$dataProvider->setTotalCount(1000);
This will make $this->getTotalCount() = 1000 and Keep the pagination.
Go here and here for more reference.