如何使用Php在JSON中表示一对多关系？

Question

I have a MySQL table that has two columns customer_id and item_id,

customer_id can have multiple item_id, (One to many relationships),

How can I represent/loop through the returned query generate a JSON output (similar to the structure above) ,using MySQL and PHP?

for example, I want my JSON output to look like this:

  {
        "data": 
         {
            "customer_id": "10",
            "item_id": " 1"
          },
         {
           "customer_id": "10",
            "item_id": " 2"
         },
  {
           "customer_id": "10",
           "item_id": " 3"
         }
   }

thanks.

Answer 1

I guess you will be getting the data from the MySQL.

$results = mysqli_query("SELECT customer_id, item_id FROM your_table_name");
$data = array();
while($result = mysqli_fetch_assoc($results)) {
     $data['data'][] = $result;
}

echo json_encode($data);

Answer 2

There are many ways to do this. Here is a suggestion.

$data = [
    'Customer' => [
        'customer_id' => 29973,
    ],
    'Item' => [
        ['item_id' => 1 ],
        ['item_id' => 2 ],
        ['item_id' => 3 ]
    ]
];

echo json_encode($data) . "\n";

Output:

{
    "Customer": {
        "customer_id": 29973
    },
    "Item": [
        {
            "item_id": 1
        },
        {
            "item_id": 2
        },
        {
            "item_id": 3
        }
    ]
}