在运行query，codeigniter时无法从数据库中检索用户信息

Question

I am having an issue, it should be very simple but I can't seem to fix it. I am trying to grab a user id from a user by searching the username in the database. But i am just getting a null value.. Please let me know what I might be doing wrong.

Here is the code for the query:

private function get_u_id($user){
    $sql = "SELECT * FROM users WHERE 'username'=?";
    $query = $this->db->query($sql, array($user));
    foreach($query->result as $row){
    return $row['id'];
    }
}

I am storing this info in a session so here is that code:

$user_session_data = array(
   'user'=>$p_info['username'],
   'email' => $this->get_user_email($p_info['username']),
   'u_id' => $this->get_u_id($p_info['username']),
   'validated' => TRUE
);

//set a session, (username, email, user_id)

private function set_session($user_data) {
        $this->session->set_userdata($user_data);
    }

And when I output this session using print_r() it looks like this

[user_data] => [user] => wilprim [email] => [u_id] => [validated] => 1 

Answer 1

You've got incorrect quotes in the query:

$sql = "SELECT * FROM users WHERE 'username'=?";
                                  ^--      ^--

'username' is a STRING, not a fieldname. username is also not a reserved word, so there's absolutely no need to quote it anyways.

User either of:

$sql = "SELECT * FROM users WHERE `username`=?"; // note the backticks
$sql = "SELECT * FROM users WHERE username=?"; // no quotes at all

As written, the only way your query would ever return any data is if you had a user whose username was literally username.