Question

有人可以帮助我检查表用户是否有用户名？我正在使用SQLite3，PHP和PDO，我编写了像

这样的代码

 try {
    $db = new PDO('sqlite:/var/db/db_users.db');
    $query = 'SELECT COUNT(*) FROM users WHERE username= :username';// moze LIMIT 1 da se stavi jer je sigurno jedan sa istim username i password sine
    $sth = $db->prepare($query, array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
    $sth->execute(array(':username' => $username));
    $result = $sth->fetchAll();
} catch (Exception $e) {
    return (array('message' => 'error'));
}

但没有single_fetch或我找不到。任何人都可以帮我解决这个问题吗？

Answer 1

只需使用一次获取..因为只有一行你jsut像普通一样获取它而不是循环然后关闭光标。如果你只是在特定值之后，你也可以突然拉出这个列......

try {
    $db = new PDO('sqlite:/var/db/db_users.db');

    // add an alias.. not really necessary but good practice
    $query = 'SELECT COUNT(*) AS usercount FROM users WHERE username= :username';

    $sth = $db->prepare($query);
    $sth->execute(array(':username' => $username));

    // just call regular fetch for the first an only result
    // use fetch(PDO::FETCH_COLUMN) or fetchColumn to jsut get 
    // a single column value from the row
    $result = $sth->fetchColumn(0);

    // be nice and close the cursor since we are done.
    $sth->closeCursor();

} catch (Exception $e) {
    return (array('message' => 'error'));
}

任何人都可以帮我检查表用户是否有用户名？

1 个答案: