Question

我有一个返回用户ID的select语句：

        $stmt = $dbh->prepare("SELECT user_id FROM users WHERE username = '" . $user_name . "'");   
        $stmt->execute();
        $row = $stmt->fetch(PDO::FETCH_ASSOC);

        $user_id = $row['user_id'];

这工作正常，但当我调用一个应该返回朋友ID的函数时:(选择语句）

function get_friend($friend_username){

#create the PDO object 
/**
 * Used to instanciate the host of the server
 * @var string
 */
    $hostname = 'localhost';
            /**
 * Used to instanciate the username to connect to the server
 * @var string
 */
    $username = 'ODBC';
            /**
 * Used to instanciate the password to connect to the server
 * @var string
 */
    $pass = "";
            /**
 * Used to instanciate the database name
 * @var string
 */
    $db_name = 'bloggie_db';
    try{
        $dbh = new PDO("mysql:host=$hostname;dbname=$db_name" , $username, $pass);

        #set PDO error mode to exception 
        $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $stmt = $dbh->prepare("SELECT user_id FROM users WHERE username = '" . $friend_username . "'"); 
        $stmt->execute();
        $row = $stmt->fetch(PDO::FETCH_ASSOC);

        $friend_id = $row['user_id'];   
        return $friend_id;
    }catch(PDOException $e){
        $e->getTrace();
    }
    $dbh = null;
} //The whole get friend function

函数调用：

        $friend_id = $this->get_friend($friend_user_name);

如果我将$ friend_user_name替换为数据库中的值＆＃39; testing@bloggie.com'，则不返回任何内容，然后返回$ friend_id。为什么当我使用变量时它不会返回但是当我使用实际值时它会返回。

Answer 1

我想出来了。通过锚标记将朋友ID发送到调用函数的页面完美地工作。谢谢你的帮助。

Php pdo SELECT语句没有返回我需要的值

1 个答案: