mam taką tablicę

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array:164 [▼
  "2019-06-27" => array:2 [▼
    0 => array:6 [▼
      "date" => "2019-06-27"
      "day" => "26"
      "quantity" => 4998
      "water" => 879.648
      "feed" => 494802
      "weight" => 4548180
    ]
    1 => array:6 [▼
      "date" => "2019-06-27"
      "day" => "6"
      "quantity" => 1000
      "water" => 43.0
      "feed" => 31000
      "weight" => 160000
    ]
  ]
  "2019-06-28" => array:2 [▶]
  "2019-06-29" => array:2 [▶]
  "2019-06-30" => array:1 [▶]
  "2019-07-01" => array:1 [▶]
  "2019-07-02" => array:1 [▶]
 
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potrzebuję zsumować to co przedstawiłem rozwinięte powyżej. Suma quantity, water, etc...
Tak aby po tej operacji każdy klucz ( w moim przypadku data ) miałą jedną tablicę.

Punkt w którym się zatrzymałem.

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foreach($mojaTablica as $key => $val)
        {
            if(count($val) > 1)
            {
                $tmp = array();
 
                foreach($val as $k => $v)
                {
                    // $arrKeys = array_keys($v);
                    // 
                }
            }
        }
[PHP] pobierz, plaintext 

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$input = [
    '2019-06-27' => [
        [
            "date" => "2019-06-27",
            "day" => "26",
            "quantity" => 4998,
            "water" => 879.648,
            "feed" => 494802,
            "weight" => 4548180,
        ],
        [
            "date" => "2019-06-27",
            "day" => "6",
            "quantity" => 1000,
            "water" => 43.0,
            "feed" => 31000,
            "weight" => 160000,
        ]
    ],
];
 
$output = [];
 
foreach ($input as $date => $values) {
    foreach ($values as $value) {
        if (empty($output[$value['date']]['quantity'])) {
            $output[$value['date']]['quantity'] = 0.00;
        }
 
        if (empty($output[$value['date']]['water'])) {
            $output[$value['date']]['water'] = 0.00;
        }
 
        if (empty($output[$value['date']]['feed'])) {
            $output[$value['date']]['feed'] = 0;
        }
 
        if (empty($output[$value['date']]['weight'])) {
            $output[$value['date']]['weight'] = 0;
        }
 
        $output[$value['date']]['quantity'] += $value['quantity'];
        $output[$value['date']]['water'] += $value['water'];
        $output[$value['date']]['feed'] += $value['feed'];
        $output[$value['date']]['weight'] += $value['weight'];
    }
}
 
var_dump($output);
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