合并具有公共id的多维数组

Question

我有两个多维数组：

第一批披萨：

0 => array:2 [▼
    "pizza_id" => 11
    "pizza_name" => "Hawaï"
]
1 => array:2 [▼
    "pizza_id" => 12
    "pizza_name" => "Tonno"
]
2 => array:2 [▼
    "pizza_id" => 13
    "pizza_name" => "Surprise"
]

第二列成分：

0 => array:4 [▼
    "pizza_id" => 11
    "ingredient_one" => "Ananas"
    "ingredient_two" => "Onion"
    "ingredient_three" => "Ham"
]
1 => array:4 [▼
    "pizza_id" => 12
    "ingredient_one" => "Tuna"
    "ingredient_two" => "Onion"
    "ingredient_three" => null
]

我想合并这两个通过 pizza_id 链接的数组。其中一个 Pizza ID 没有匹配的配料数组（配料未知）所以对于这个 Pizza，我想将配料设置为 null 并获取下一个数组：

新数组 PizzaAndIngredients：

0 => array:5 [▼
    "pizza_cid" => 11
    "pizza_name" => "Hawaï"
    "ingredient_one" => "Ananas"
    "ingredient_two" => "Onion"
    "ingredient_three" => "Ham"
]
1 => array:5 [▼
    "pizza_id" => 12
    "pizza_name" => "Tonno"
    "ingredient_one" => "Tuna"
    "ingredient_two" => "Onion"
    "ingredient_three" => null
]
2 => array:5 [▼
    "pizza_id" => 13
    "pizza_name" => "Surprise"
    "ingredient_one" => null
    "ingredient_two" => null
    "ingredient_three" => null
]

我一直在摆弄array_merge、foreach等，但无法获取数组。另一种方法是构建一个新查询并左连接比萨饼和配料，但在现实生活中，数组要复杂得多，这意味着要重复大量代码。

我希望有一个更有效的合并两个多维数组的解决方案。

我最后一次尝试是：

$PizzaAndIngredients = array();
foreach ($pizzas as $key => $values) {
    $PizzaAndIngredients[$key] = array_merge($ingredients, $values);
}

Answer 1

当您从查询结果中获取行时，您可以将数组键设置为等于 pizza_id，或者通过 pizza_id:

重新索引它们

$pizza       = array_column($pizza, null, 'pizza_id');
$ingredients = array_column($ingredients, null, 'pizza_id');

然后创建一个默认的 null 数组以供在 $ingredients 不存在时使用，然后将 $ingredients 值与 $pizza 值合并：

//get an ingredient array
$temp    = reset($ingredients);
//combine keys and an array of nulls
$default = array_combine(array_keys($temp),
                         array_fill(0, count($temp), null));

foreach($pizza as $id => $p_values) {
    //check if $ingredients[$id] exists, if not use the default
    $i_values    = isset($ingredients[$id]) ? $ingredients[$id] : $default;
    //you can also use just $result[] if you don't need the pizza_id as key
    $result[$id] = array_merge($i_values, $p_values); 
}

合并具有公共id的多维数组

Merge multi-dimensional arrays with common id

php

arrays

array-merge