Magento 2 Product Collection Cheat Sheet by DominicXigen

use Magento\Catalog\Model\ResourceModel\Product\CollectionFactory as ProductCollectionFactory;

/**
 * @var ProductCollectionFactory
 */
private $productCollectionFactory;

/**
 * @param ProductCollectionFactory $productCollectionFactory
 */
public function __construct(
    ProductCollectionFactory $productCollectionFactory
) {
    $this->productCollectionFactory = $productCollectionFactory;
}

\Magento\Catalog\Model\Product\Type::TYPE_SIMPLE 
\Magento\Catalog\Model\Product\Type::TYPE_BUNDLE 
\Magento\Catalog\Model\Product\Type::TYPE_VIRTUAL 
\Magento\Downloadable\Model\Product\Type::TYPE_DOWNLOADABLE 
\Magento\ConfigurableProduct\Model\Product\Type\Configurable::TYPE_CODE 
\Magento\GroupedProduct\Model\Product\Type\Grouped::TYPE_CODE

/**
 * @var \Magento\Catalog\Model\Product\Visibility
 */
protected $productVisibility;

public function __construct(
    \Magento\Catalog\Model\Product\Visibility $productVisibility,
) {
    $this->productVisibility = $productVisibility;
}

[...]
$collection->setVisibility($this->productVisibility->getVisibleInSiteIds());
[...]

// Is Equal To
$collection->addAttributeToFilter('status', ['eq' => 1]);

// Is Not Equal To
$collection->addAttributeToFilter('visibility', ['neq' => 1]);

// Greater Than
$collection->addAttributeToFilter('price', ['gt' => 3]);

// Less Than
$collection->addAttributeToFilter('price', ['lt' => 3]);

// Greater Than or Equal To
$collection->addAttributeToFilter('price', ['gteq' => 4]);

// Less Than or Equal To
$collection->addAttributeToFilter('price', ['lteq' => 4]);

// Contains – with % wildcards
$collection->addAttributeToFilter('sku', ['like' => 'DVD%']);

// Does Not Contain – with % wildcards
$collection->addAttributeToFilter('sku', ['nlike' => 'ABC%']);

// In Array
$collection->addAttributeToFilter('entity_id', ['in' => [1,3,12]]);

// Not In Array
$collection->addAttributeToFilter('entity_id', ['nin' => [1,2,12]]);

// Is NULL
$collection->addAttributeToFilter('description', 'null');
$collection->addAttributeToFilter('description', ['null' => true]);

// Is Not NULL
$collection->addAttributeToFilter('description', 'notnull');
$collection->addAttributeToFilter('description', ['notnull' => true]);

$collection->addPriceData();

$collection->addAttributeToFilter('type_id', $typeFilter);

$collection->addAttributeToFilter(
    'status',
    ['in' => 'processing']
);

// Or
$collection->addAttributeToFilter([ 
    [
        'attribute' => 'download_link', 
        'null'      => true, 
    ], 
    [ 
        'attribute' => 'download_link', 
        'eq'        => '', 
    ], 
]);

/**
 * @var \Magento\CatalogInventory\Helper\Stock
 */
protected $stockHelper;

 public function __construct(
     \Magento\CatalogInventory\Helper\Stock $stockHelper
) {
     $this->stockHelper = $stockHelper;
}

[...]
$this->stockFilter->addInStockFilterToCollection($collection);
[...]

$collection->getMaxPrice();
$collection->getMinPrice();
$collection->getPriceStandardDeviation();
$collection->getPricesCount();

$collection = $this->productCollectionFactory->create();

$collection->addIdFilter($productId);

$collection->addStoreFilter($storeId);

$collection->addAttributeToSelect($attributeCode);

return $collection->getFirstItem();

return $collection->getFirstItem()->getData($attributeCode);

/**
 * @var Magento\Catalog\Model\Product\Attribute\Source\Status
 */
protected $productStatus;

public function __construct(
    \Magento\Catalog\Model\Product\Attribute\Source\Status $productStatus
) {
    $this->productStatus = $productStatus;
}

[...]
$collection->addAttributeToFilter(
    'status',
    ['in' => $this->productStatus->getVisibleStatusIds()
]);
[...]

$collection->addCategoryFilter($category);

return $collection->getAllIds();

echo (string) $collection->getSelect();
$collection->printLogQuery(true);

$collection->addMediaGalleryData();

$collection->addTierPriceData();
$collection->addTierPriceDataByGroupId($customerGroupId);

$collection->addCategoryIds();

$collection->addWebsiteNamesToResult();

$collection->joinField(
    'qty',
    'cataloginventory_stock_item',
    'qty',
    'product_id=entity_id',
    '{{table}}.stock_id=1',
    'left'
);

// Sort Collection 
// Order by Attribute Ascending 
$collection->setOrder('price', 'ASC'); 
 
// Order by Attribute Descending 
$collection->setOrder('name', 'DESC'); 

// Random Order 
$collection->setOrder('rand()'); 

// Limit Collection 
$collection->setPageSize(10); 
$collection->setCurPage(1); 
 
// Count Results 
$collection->count();

$collection->addUrlRewrite($categoryId);

$collection->addTaxPercents();

$collection->addOptionsToResult();

$collection->addAttributeToSort('name', 'DESC');

$collection->clear();