Fetching results

class Model

Model linked to a persistence is your “window” into DataSet and you get several ways which allow you to fetch the data.

Iterate through model data


Create your persistence object first then iterate it:

$db = \Atk4\Data\Persistence::connect($dsn);
$m = new Model_Client($db);

foreach ($m as $id => $item) {
    echo $id . ': ' . $item->get('name') . "\n";

You must be aware that $item will actually be same as $m and will point to the model. The model, however, will have the data loaded for you, so you can call methods for each iteration like this:

foreach ($m as $item) {


Currently ATK Data does not create new copy of your model object for every row. Instead the same object is re-used, simply $item->getDataRef() is modified by the iterator. For new users this may be surprising that $item is the same object through the iterator, but for now it’s the most CPU-efficient way.

Additionally model will execute necessary after-load hooks that might trigger some other calculation or validations.


changing query parameter during iteration will has no effect until you finish iterating.

Keeping models

If you wish to preserve the objects that you have loaded (not recommended as they will consume memory), you can do it like this:

$cat = [];

foreach (new Model_Category($db) as $id => $c) {
    $cat[$id] = clone $c;

Raw Data Fetching


If you do not care about the hooks and simply wish to get the data, you can fetch it:

foreach ($m->getRawIterator() as $row) {
    var_dump($row); // array

The $row will also contain value for “id” and it’s up to you to find it yourself if you need it.


Will fetch and output array of hashes which will represent entirety of data-set. Similarly to other methods, this will have the data mapped into your fields for you and server-side expressions executed that are embedded in the query.

By default - onlyFields will be presented as well as system fields.

Fetching data through action

You can invoke and iterate action (particularly SQL) to fetch the data:

foreach ($m->action('select') as $row) {
    var_dump($row); // array

This has the identical behavior to $m->getRawIterator();

Comparison of various ways of fetching

  • getIterator - action(select), [ fetches row, set ID/Data, call afterLoad hook, yields model ], unloads data
  • getRawIterator - action(select), [ fetches row, yields row ]
  • export - action(select), fetches all rows, returns all rows