内连接一个表中的两个外键

Question

我有查询 sql 进行搜索。我有两个表要进行内连接。这是我的桌子：

table_order
------------
id_order  id_user_order  id_user_taker  status
1          2              3              done
2          2              4              done

table_user
--------------
id_user    name
1          Alex
2          Jason
3          Danis
4          Lorent

我会像这样内部加入：

<?php
include'conn.php'
$qry = $conn->query("select table_order.*, table_user.name AS order_name, table_user.name AS taker_name FROM table_order INNER JOIN table_user ON table_user.id_user = table_order.id_user_order INNER JOIN table_user ON table_user.id_user = table_order.id_user_taker ");

while($data = $qry->fetch_assoc()){
echo $data['order_name'] . " " . $data['taker_name'];
}

?>

但是，不能显示。请解决我的问题伙计们。非常感谢

Answer 1

当您需要两次或多次加入同一个表时，您必须为表使用适当的别名

 $qry = $conn->query("select 
              table_order.*
            , a.name AS order_name
            , b.name AS taker_name 
            FROM table_order 
            INNER JOIN table_user as a ON a.id_user = table_order.id_user_order 
            INNER JOIN table_user as b ON b.id_user = table_order.id_user_taker ");