php - 如何在一个数组PHP中设置子json数组

Question

我是 php 的新手，我试图获取从以下响应中获得的数据，但我想将此数据设置在子数组中。这该怎么做？我有两个不同的表 category 和 Product。如何明智地显示多个产品类别。

提前致谢!

{
    "data" : [
        {
            "id" : "1",
            "recipe_name" : "Tofu Tikka",
            "ingredients" : "Firm tofu 1 pack (bite sized cube)\r\n",
            "prepration" : "Press tofu with the help of plate to remove moisture 
   and leave for 30-40 minutes, then cut in cubes.\r\n",
            "category_id":"1",
            "category_name":"Today's Menu"
        }
    ]
}

如何像下面这样在子数组中设置上面的响应

{
    "data":[
        "category_id":"1",
        "category_name":"Today's Menu"
        "recipes::[
            {
                "id":"1",
                "recipe_name":"Tofu Tikka",
                "ingredients":"Firm tofu 1 pack ",
                "prepration":"Press tofu with the help of plate"
            }, {
                "id":"2",
                "recipe_name":"Tikka Paneer",
                "ingredients":"Firm tofu 1 pack ",
                "prepration":"Press tofu with the help of plate"
            },
        ]
    ]
}

下面是我的 PHP 文件

<?php
    // required headers
    header("Access-Control-Allow-Origin: *");
    header("Content-Type: application/json; charset=UTF-8");

    // include database and object files
    include_once '../config/database.php';
    include_once '../objects/product.php';

    // instantiate database and product object
    $database = new Database();
    $db = $database->getConnection();

    // initialize object
    $product = new Product($db);

    // query products
    $stmt = $product->read();
    $num = $stmt->rowCount();

    // check if more than 0 record found
    if ($num>0) {

        // products array
        $products_arr=array();
        $products_arr["data"]=array();

        // retrieve our table contents
        // fetch() is faster than fetchAll()
        // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop
        while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
            // extract row
            // this will make $row['name'] to
            // just $name only
            extract($row);

            $product_item=array(
                "id" => $id,
                "recipe_name" => $recipe_name,
                "ingredients" => html_entity_decode($ingredients),
                "prepration" => $prepration,
                "category_id" => $category_id,
                "category_name" => $category_name
            );

            array_push($products_arr["data"], $product_item);
        }

        echo json_encode($products_arr);

    } else {
        echo json_encode(
        array("message" => "No products found.")
        );
    }
?>

Answer 1

在您的 while 循环中，您可以先通过 category_id 对食谱进行分组，而不是推送整个行数组。然后使用 array_values() 重新索引。

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    // extract row
    // this will make $row['name'] to
    // just $name only
    extract($row);

    // Check if category_id is already set
    if (!array_key_exists($category_id, $products_arr["data"])) {
        $products_arr["data"][$category_id] = array(
            "category_id" => $category_id,
            "category_name" => $category_name,
            "recipes" => []
            );
    }
    // Push the recipe details
    $products_arr["data"][$category_id]["recipes"][] = array(
        "id" => $id,
        "recipe_name" => $recipe_name,
        "ingredients" => html_entity_decode($ingredients),
        "prepration" => $prepration
    );

    $products_arr["data"] = array_values($products_arr["data"]);
}

echo json_encode($products_arr);

注意:输出与您的预期结果略有不同。因为输出的 data 键具有基于类别的数组，而不是具有 category_id。如果您使用 category_id 作为 data

中的键，防止多个类别被覆盖