如何在 laravel 关系中使用 where？

Question

I have a relationship on Orders and Customers .
a row from customers table:

customer_id	customer_name	customer_state	customer_city
1	Amin	Yazd	Yazd

a row from orders table:

order_id	customer_id	product_id	factor_id
1	1	3	4

Now I want order rows where customer_state is yazd.

Order.php

public function customer()
{
    return $this->belongsToMany(Customer::class, 'orders', 'order_id', 'customer_id');
}

OrdersController.php

$state = "Yazd";
$reportItem = Order::whereHas("customer", function ($query) use ($state) {
    $query->where('customer_state', $state)->get();
});

It doesn't work. How I can handle this?

Answer 1

You have put get() at the wrong place.

Change this

$reportItem = Order::whereHas("customer", function ($query) use ($state) {
    $query->where('customer_state', $state)->get();
});

To

$reportItem = Order::whereHas("customer", function ($query) use ($state) {
    $query->where('customer_state', $state);
})->get();

Learn more about laravel relations

Answer 2

What I understand from the given input you're not using the proper relation here: The belongsToMany relation is used for many-to-many relations using an allocation table. But you are actually using a one-to-many relation => one customer can have many orders. In this case you should use a belongsTo relation on Order Model or/and a hasMany relation on Customer Model:

// Order.php

public function customer() {
    return $this->belongsTo(Customer::class)
}

// Customer.php

public function orders() {
    return $this->hasMany(Order::class)
}