how to set group by and order by for custom model collection query in magento 2.3.4

Question

$Custommodel=$this->mycustommodelFactory->create();

$collection = $Custommodel->getCollection()->addFieldToFilter("customer_id",$customerid);

$collection->getSelect()->group('product_id')->order("viewed_date DESC");

while implement this way i getting wrong ordered records

what mistake there??

here this query runing magento SELECT main_table.* FROM wac_viewed_products AS main_table WHERE (customer_id = '4') GROUP BY product_id ORDER BY viewed_date DESC

Answer 1

Try with below code,

$collection = $this->collectionFactory->create()
           ->addFieldToFilter('id', $id)
           ->addFieldToFilter('status', 'Enable');

$collection->getSelect()->group('posts_id')->order('id DESC');