php - 如何获取数组中某些数组的值之和？

Question

这个问题已经有答案了:

奥 git _a (4 个回答)

已关闭 5 个月前。

如何获得每个月的存款总额和取款总额？例如(所有一月份的总存款和总提款)来自数组。

实际上，我有一些 table (100+)。每个表都有很多记录，其中包含存款、取款和日期列字段。我必须将按日期分组的存款和取款金额相加。

确实，我得到了每张 table 的每月总存款和总提款金额。现在，我必须对所有表格中的每个月进行求和。例如，所有表的一月份存取款总额。

在我的 CI Controller 中:

$all_table_id = $this->admin_model->get_all_id();

foreach ($all_table_id as $table_id)
{
    // $table_id['accountNo'] is generated table name 
    // e.g baby_ld_account_45456 ,baby_ld_account_12345

    $tableName = "baby_ld_account_" . $table_id['accountNo'];

    $single_table_monthly_data = $this->admin_model->get_monthly_data_each_table($tableName);

    // print_r($single_table_monthly_data);

    $all_table_monthly_data[] = $single_table_monthly_data;

    print_r($monthly_data);
}

在我的 CI 模型中:

public function get_monthly_data_each_table($tableName) {
    $sql = "SELECT DATE_FORMAT(`entryDate`,'%M') as Month, 
                   SUM(`deposit`) AS `Deposit`, 
                   SUM(`withDraw`) AS `Withdraw` 
            FROM $tableName 
            WHERE YEAR(`entryDate`) = YEAR(CURDATE()) 
            GROUP BY DATE_FORMAT(`entryDate`,'%M')";

    $query = $this->db->query($sql);
    $result = $query->result_array($query);

    return $result;
}

数组结果:

Array (
    [0] => Array ( 
        [0] => Array ( [Month] => January [Deposit] => 4000 [Withdraw] => 8000 )
        [1] => Array ( [Month] => February [Deposit] => 200 [Withdraw] => 5000 )
    )

    [1] => Array (
        [0] => Array ( [Month] => January [Deposit] => 1000 [Withdraw] => 1000 )
        [1] => Array ( [Month] => February [Deposit] => 3000 [Withdraw] => 6000 )
    )
    [2] => Array (
        [0] => Array ( [Month] => January [Deposit] => 6000 [Withdraw] => 2000 )
        [1] => Array ( [Month] => February [Deposit] => 4000 [Withdraw] => 8000 )
    )

    [3] => Array (
        [0] => Array ( [Month] => January [Deposit] => 3500 [Withdraw] => 2000 )
        [1] => Array ( [Month] => February [Deposit] => 1200 [Withdraw] => 5000 )
    )
)

谁能给我一个解决方案吗？

Answer 1

正如评论中指出的那样，最好使用 SQL 查询来完成。

但是你肯定可以用 PHP 做到这一点:

$result = array_reduce(
    array_reduce($array, 'array_merge', []), // Flattern array.
    function ($result, $item) {
        // Extract array elements to variables, for the sake of easier use.
        extract($item);

        // If there's no entry for current month - create emtpy entry.
        if (!isset($result[$Month])) {
            $result[$Month] = [
                'Deposit' => 0,
                'Withdraw' => 0
            ];
        }

        // Add current amounts.
        $result[$Month]['Deposit'] += $Deposit;
        $result[$Month]['Withdraw'] += $Withdraw;

        return $result;
    },
    []
);

这里是working demo .