如何將一列添加到mysqli中的更多表中？

Question

首先，我選擇一個表來讀取ID列

$db_hand1 = mysqli_connect($server, "root", "password",$database1); 
$result = mysqli_query($db_hand1, "SELECT id FROM table"); 

值現在我想一個列添加到表中的另一個數據庫：

$db_hand2 = mysqli_connect($server, "root", "password",$database2); 

while($row = mysqli_fetch_array($result)){ 
    $user_id= $row['id']; 
    $result = mysqli_query($db_hand2,"ALTER TABLE $user_id ADD us_id INT(1) NULL DEFAULT '1'"); 
} 

然而，這而不起作用。它總是在第一個表中添加一列。當我這樣做manualy：

$db_hand2 = mysqli_connect($server, "root", "password",$database2); 
$user_id= "table_name"; 
$result = mysqli_query($db_hand2,"ALTER TABLE $user_id ADD us_id INT(1) NULL DEFAULT '1'"); 

和manualy設置$ user_ID的爲表的名稱它的工作原理。

Answer 1

您覆蓋$result，改變像

$db_hand2 = mysqli_connect($server, "root", "password",$database2); 

    while($row = mysqli_fetch_array($result)){ 
     $user_id= $row['id']; 
     $result_alter = mysqli_query($db_hand2,"ALTER TABLE $user_id ADD us_id INT(1) NULL DEFAULT '1'"); 
    }