using sum with relation Laravel Eloquent ORM - sql

Question

i have Model Material which has
protected $with = ['costPrices'];
public function costPrices(){
return $this->hasMany(CostPrice::class);
}
the table of cost_prices has multiple quantity
//create_cost_prices_table
Schema::create('cost_prices', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('material_id');
$table->unsignedBigInteger('supplier_id');
$table->integer('quantity');
$table->timestamps();
});
i want to get (insufficient materials ) in another way select all materials form materials table where sum of all quantities of cost_prices table < 3 and get me the resulted materials not the count

Answer 1

You have 2 options:
You could fix your option with whereHas() by adding select and groupBy:
$materials = Material
::whereHas('costPrices', function($q) {
$q
->select('meterial_id')
->groupBy('material_id')
->havingRaw('SUM(quantity) > 4');
})
->get();
Or use subquery:
For laravel 6.x:
$materials = Material
::addSelect([
'cost_prices_sum' => CostPrice::selectRaw('sum(quantity)')->whereColumn('material_id', 'material.id')
])
->having('cost_prices_sum', '>', 4)
->get();
For laravel 5.x:
$materials = Material
::selectRaw('carts.*, (select sum(quantity) from cost_prices where cost_prices.matrerial_id = meterials.id) as cost_prices_sum')
->having('cost_prices_sum', '>', 4)
->get();
UPDATE: option with whereHas() is faster on a large number of rows.