php - 如何从sql数据库中的2个表中获取多列数据？

Question

我有 2 个表，分别命名为 shipping_infos 和 orders。我想从 2 个表中获取多个列。这 2 个表共享一个相同的列，即 user_id 列。我一直在尝试这段代码，但它仍然返回 null。应该怎么写？

 <?php
  include ('classes/functions.php');

 if(isset($_POST['user_id'])){
 $user_id = $_POST['user_id'];
 $check_receipt = "select 
shipping_infos.shipping_name,shipping_infos.shipping_address,
shipping_infos.shipping_contact,shipping_infos.shipping_email,  
  orders.order_date,orders.trx_id,orders.tracking_num from
 shipping_infos inner join orders on shipping_infos.user_id = orders.user_id    
 where user_id= '".$user_id."';";
        $run_receipt_checking = mysqli_query($con, $check_receipt);
        $result = array();
    while($row = mysqli_fetch_array($run_receipt_checking)){
    array_push($result,
    array(
          'shipping_name'=>$row[2],
          'shipping_address'=>$row[3],
          'shipping_contact'=>$row[4],
          'shipping_email'=>$row[5],
          'order_date'=>$row[8],
          'trx_id'=>$row[1],
          'tracking_num'=>$row[2],            
));
}
    echo json_encode(array("result"=>$result));
} ?>

Answer 1

试试这个查询:

$check_receipt = "select  si.shipping_name,
        si.shipping_address,
        si.shipping_contact,
        si.shipping_email,
        o.order_date,
        o.trx_id,
        o.tracking_num 
from shipping_infos si
inner join orders o
    on si.user_id = o.user_id    
where si.user_id='".$user_id."';";

并在此处更改:

    array_push($result,
    array(
          'shipping_name'=>$row[0],
          'shipping_address'=>$row[1],
          'shipping_contact'=>$row[2],
          'shipping_email'=>$row[3],
          'order_date'=>$row[4],
          'trx_id'=>$row[5],
          'tracking_num'=>$row[6],            
));