1

我有 2 个 MySQL 表，在其中使用以下 SQL 语句提取数据：

分类：SELECT cat_id, cat_name FROM categories

产品：SELECT pro_id, pro_name, pro_category FROM products

当然pro_category是外键cat_id

我想获得以下 JSON 数据：

"categories":[
    {
        "id": 1,
        "name": "Guitars",
        "products":[
            {
                "id": 1,
                "name": "Fender Statocaster"
            },
            {
                "id": 2,
                "name": "Gibson Les Paul"
            }
        ]
    },
    {
        "id": 2,
        "name": "Basses",
        "products":[
            {
                "id": 3,
                "name": "Fender Jazz Bass"
            },
            {
                "id": 4,
                "name": "MusicMan StingRay"
            }
        ]
    }   
]

所以我必须做一个类别数组，并且对于每个元素，一个产品子数组（然后我会去json_encode()）。

遍历类别并创建第一个数组非常容易，但我完全坚持如何创建产品子数组......这是我的代码，问号是我停下来的地方，因为我不知道该怎么办：

$categories = array();
while ($row_rsCategories = mysql_fetch_assoc($rsCategories)) { 
    $categories[] = array(
        'id' => $row_rsCategories['cat_id'],
        'name' => $row_rsCategories['cat_name'],
        'products' => array(
            ???????
        ),
    );
}

请问，你能帮忙吗？
谢谢！

4

3 回答 3

5 
$categories = array();
while ($row_rsCategories = mysql_fetch_assoc($rsCategories)) { 

    $product_array = array();
    $product_array_query = mysql_query("SELECT pro_id, pro_name, pro_category FROM products WHERE pro_category = '".$row_rsCategories['cat_id']."'");

    while($product_array_fetch = mysql_fetch_array($product_array_query)) {

       $product_array[] = array("id"=>$product_array_fetch['pro_id'],"name"=>$product_array_fetch['pro_name']);

    }                

    $categories[] = array(
        'id' => $row_rsCategories['cat_id'],
        'name' => $row_rsCategories['cat_name'],
        'products' => $product_array,
    );
}
于 2013-03-23T12:59:24.050 回答
0 
$categories = array();
while ($row_rsCategories = mysql_fetch_assoc($rsCategories)) { 
    $categories[$row_rsCategories['cat_id']] = array(
        'id' => $row_rsCategories['cat_id'],
        'name' => $row_rsCategories['cat_name'],
        'products' => array(),
    );
}

while ($row_rsProducts = mysql_fetch_assoc($rsProducts)) {
    $categories[$row_rsProducts['pro_category']]['products'][] = array(
         'id' => $row_rsProducts['pro_id'],
         'name' => $row_rsProducts['pro_name'],
    );
}
于 2013-03-23T13:03:55.367 回答
-1

我使用JOIN查询按其类别 id 订购产品，这样属于某个类别的产品就会聚集在一起。cat_id如果您看到更改，则遍历结果数组并创建新类别。

$db = new PDO($connectionString);

$sql = "SELECT * FROM products t1 LEFT JOIN categories t2 ON t1.pro_category = t2.cat_id ORDER BY t2.cat_id";
$stmt = $db->prepare($sql);
if($stmt->execute())
{
    $rows = $stmt->fetchAll();
    $currentCategory = NULL;
    $categories = array();
    foreach($rows as $r)
    {
        if ($currentCategory == NULL || $r['cat_id' != $currentCategory['id'])
        {
            $currentCategory = array(
                'id' => $r['cat_id'],
                'name' => $r['cat_name'],
                'products' => array();
            );
            $categories[] = $currentCategory;
        }
        $currentCategory['products'][] = array(
            'id' => 'pro_id',
            'name' => 'pro_name',
        )
    }
}
else
{
    var_dump($stmt->errorInfo());
}
于 2013-03-23T13:06:48.833 回答