php - 将数组中的两列相乘并求出它们的总和

Question

我有一个按数据库查询中的日期分组的数组结构(见下文)，我希望通过将数量乘以交易金额来找到每个组的总数>.

这是我到目前为止所拥有的:

    array (size=3)
    '2017-7-03' =>
            array (size=3)
            0 =>
                    array (size=4)
                    'paydate' => string '2017-7-03' (length=9)
                    'tariff' => string 'batch1' (length=31)
                    'quantity' => string '1.0000' (length=6)
                    'transamount' => string '20.0000' (length=7)
            1 =>
                    array (size=4)
                    'paydate' => string '2017-7-03' (length=9)
                    'tariff' => string 'Eye Test' (length=8)
                    'quantity' => string '1.0000' (length=6)
                    'transamount' => string '5.0000' (length=6)
            2 =>
                    array (size=4)
                    'paydate' => string '2017-7-03' (length=9)
                    'tariff' => string 'hub photos' (length=16)
                    'quantity' => string '1.0000' (length=6)
                    'transamount' => string '82.0000' (length=7)
                    '2017-7-04' =>
            array (size=9)
            0 =>
                    array (size=4)
                    'paydate' => string '2017-7-04' (length=9)
                    'tariff' => string ' Register' (length=21)
                    'quantity' => string '1.0000' (length=6)
                    'transamount' => string '20.0000' (length=7)

目的是获得按日期分组的所有交易的总数。

Answer 1

这可能不起作用，因为我不确定您是否需要使用日期作为键来访问交易...但是这样的东西会向每个数组项添加一个元素和总计。

// loop through the arrays sorted by date
foreach ($groups as $group)
{
    $total = 0;
    // loop through each transaction
    foreach ($group as $transaction)
    {
        // Add to the total for each purchase group
        $total += $transaction->quantity * $transaction->transamount;
    }
    // put the total into the group array
    $group->total = $total
}

有了这个，你最终应该得到类似的东西

'total' => (calculated value),     
'2017-7-03' =>
        array (size=3)
        0 =>
                array (size=4)
                'paydate' => string '2017-7-03' (length=9)
                'tariff' => string 'batch1' (length=31)
                'quantity' => string '1.0000' (length=6)
                'transamount' => string '20.0000' (length=7)
        1 =>
                array (size=4)
                'paydate' => string '2017-7-03' (length=9)
                'tariff' => string 'Eye Test' (length=8)
                'quantity' => string '1.0000' (length=6)
                'transamount' => string '5.0000' (length=6)
        2 =>
                array (size=4)
                'paydate' => string '2017-7-03' (length=9)
                'tariff' => string 'hub photos' (length=16)
                'quantity' => string '1.0000' (length=6)
                'transamount' => string '82.0000' (length=7)
                '2017-7-04' =>