Laravel sum nested relationship column - sql

Question

I tried sum nested related column but get empty result.
Code:
$data = CropType::with(['categories' => function($cq) {
return $cq->with(['varieties' => function($vq) {
return $vq->with(['products' => function($pq) {
return $pq->sum('total');
}]);
}]);
}])->get();
As you can see, I have 4 tables that are interconnected with foreign keys
Table: crop_types
id
title
Table: categories
id
title
crop_type_id
Table: varieties
id
title
category_id
Table: products
id
title
total
variety_id
But when I run my query it's run as like this instead summing total products:
"select * from crop_types"
How I can correctly sum total products in each crop type?

Answer 1

Try this query to get total products in each crop type:
SQL
SELECT crop_types.id,
crop_types.title AS title,
sum(products.total) AS total
FROM `products`
INNER JOIN `varieties`
ON `varieties`.`id` = `products`.`variety_id`
INNER JOIN `categories`
ON `categories`.`id` = `varieties`.`category_id`
INNER JOIN `crop_types`
ON `crop_types`.`id` = `categories`.`crop_type_id`
GROUP BY `crop_types`.`id`
Laravel Eloquent
$result = Product::query()
->selectRaw('crop_types.id, crop_types.title as title, sum(products.total) as total')
->join(
'varieties',
'varieties.id',
'=',
'products.variety_id'
)
->join(
'categories',
'categories.id',
'=',
'varieties.category_id'
)
->join(
'crop_types',
'crop_types.id',
'=',
'categories.crop_type_id'
)
->groupBy('crop_types.id')
->get();