Doctrine Distinct Count [closed] - php

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What is the best practice for retrieving the DISTINCT COUNT on an entity collection?
In this example entity (Customer), I have a oneToMany relationship with Orders.
I want to count how many sales & products the customer has ordered:
> select * from orders;
+----------+----------+----------+
| customer | sale_ref | prod_ref |
+----------+----------+----------+
| 1 | sale_1 | prod_1 |
| 1 | sale_1 | prod_2 |
| 1 | sale_2 | prod_1 |
| 1 | sale_3 | prod_3 |
+----------+----------+----------+
> select count(prod_ref) from order where customer = 1;
+-----------------+
| count(prod_ref) |
+-----------------+
| 4 |
+-----------------+
> select count(distinct(sale_ref)) from order where customer = 1;
+-----------------+
| count(prod_ref) |
+-----------------+
| 3 |
+-----------------+
Here is the code
use Doctrine\ORM\Mapping as ORM;
class Customer
{
/**
* #var \Doctrine\Common\Collections\Collection
* #ORM\OneToMany(targetEntity="Orders", mappedBy="customer", cascade={"persist", "remove"}, fetch="EXTRA_LAZY")
*/
protected $orders;
/**
* #return \Doctrine\Common\Collections\Collection
*/
public function getOrders(): \Doctrine\Common\Collections\Collection
{
return $this->orders;
}
/**
* #return int
*/
public function getOrdersProductCount(): int
{
return $this->orders->count();
}
}
class Orders
{
/**
* #var Customer $customer
* #ORM\ManyToOne(targetEntity="Customer", inversedBy="orders")
*/
protected $customer;
/**
* Non-unique sales reference
* #var string $salesRef
* #ORM\Column(name="sales_ref", type="string")
*/
protected $salesRef;
/**
* Unique product reference
* #var string $productRef
* #ORM\Column(name="product_ref", type="string")
*/
protected $productRef;
/**
* #return Customer
*/
public function getCustomer(): Customer
{
return $this->customer;
}
/**
* #return string
*/
public function getProductRef(): string
{
return $this->productRef;
}
/**
* #return string
*/
public function getSalesRef(): string
{
return $this->salesRef;
}
}
Using the Customer->getOrdersProductCount() works perfectly fine for retrieving the product count and is said to be "good practice" as it doesn't hit the database with full loading of the collection:
https://www.doctrine-project.org/projects/doctrine-orm/en/2.7/tutorials/extra-lazy-associations.html
If you mark an association as extra lazy the following methods on collections can be called without triggering a full load of the collection Collection#count()
However, in this example, a Customer can have multiple products for a sale - where the salesRef is non-unique. What is the best method for retrieving a DISTINCT COUNT of the salesRef?
This could/should be handled in the entity repository class:
class OrdersRepository
{
public function getSalesCount($customer): int
{
return (int)$this->createQueryBuilder('o')
->select('COUNT(DISTINCT(o.salesRef))')
->where('o.customer = :customer')
->setParameter('customer', $customer)
->setMaxResults(1)
->getQuery()
->getSingleScalarResult();
}
public function getProductCount($customer): int
{
return (int)$this->createQueryBuilder('o')
->select('COUNT(o.productRef)')
->where('o.customer = :customer')
->setParameter('customer', $customer)
->setMaxResults(1)
->getQuery()
->getSingleScalarResult();
}
}
This works BUT I need to load the entityManager/CustomerRepository in order to access these methods - whereas at least I can retrieve the product count from within the entity....
How could I access the distinct sales count from within the Customer entity - if at all?
I have considered using the Collection#filter() method and/or looping through the Orders entity to create an array with the salesRef as the key and then using array_unique#count() but this doesn't seem "right" - I suspect I know the answer (use the entity repository) but I would prefer to be able to access the sales count from within the Customer entity - what is the best practice/method?

Answer 1

I think this should do it and would be a more portable way of doing it. I did not test it though.
$qb = $this->createQueryBuilder('o');
return (int)$qb
->select($qb->expr()->countDistinct('o.salesRef'))
->where('o.customer = :customer')
->setParameter('o.customer', $customer)
->setMaxResults(1)
->getQuery()
->getSingleScalarResult();
Reference is here: https://www.doctrine-project.org/projects/doctrine-orm/en/2.7/reference/query-builder.html#the-querybuilder
Hope this helps