Question

我有2个表，customers和customer_invoices，我想让所有客户的发票都有条件，然后选择特定的列（customers.id，customers.last_name和每个客户的发票total_price的总和），我得到以下查询：

$result = Customer::whereHas('customerInvoices', function(Builder $q) {
            $q->where('customer_invoices.status', 1);
        })->select([
            'customers.id',
            'customers.last_name',
            \DB::raw('SUM(customer_invoices.total_price) as sum')
        ])->get();

customerInvoices是关系：

public function customerInvoices() {

    return $this->hasMany(CustomerInvoice::class);
}

我想使用子查询而不是联接，所以在这里我不能选择此\DB::raw('SUM(customer_invoices.total_price) as sum')，否则我当然会收到此错误：

"SQLSTATE[42S22]: Column not found: 1054 Unknown column 'customer_invoices.total_price' in 'field list' (SQL: select `customers`.`id`, `customers`.`last_name`, SUM(customer_invoices.total_price) as sum from `customers` where exists (select * from `customer_invoices` where `customers`.`id` = `customer_invoices`.`customer_id` and `customer_invoices`.`status` = 1))"

如何在不使用联接的情况下实现这一目标？

Answer 1

您可以使用withCount()从相关模型中获取总和，

@Valid

另一种求和的方法，您可以像在客户模型中定义$result = Customer::select([ 'customers.id', 'customers.last_name' ])->withCount([ 'customerInvoices as invoice_sum' => function($query) { $query->select(DB::raw('SUM(total_price)')); } ])->whereHas('customerInvoices', function(Builder $q) { $q->where('customer_invoices.status', 1); })->get();关系

hasOne()

在查询生成器中

public function invoice_sum()
{
    return $this->hasOne(CustomerInvoice::class)
        ->select('customer_id',
            DB::raw('sum(total_price)')
        )->groupBy('customer_id');
}

根据Eloquent : withCount() overrides the $columns on get()问题，首先放置$result = Customer::select([ 'customers.id', 'customers.last_name', ])->with('invoice_sum') ->whereHas('customerInvoices', function(Builder $q) { $q->where('customer_invoices.status', 1); })->get();方法，然后使用select()函数

在Laravel中使用whereHas时，从子查询中选择SUM

1 个答案: