PHP 尝试连接到数据库

Question

I'm trying to connect to a database using php but i am getting 500 server error.

<?php
session_start();
$db = new mysqli("localhost", "username", "password", "db_name") or 
die("ERROR!!!");
$sql = "SELECT forum_id, forum_name FROM forum_tabl";
if($query = $db->prepare(sql)){
   $query = bind_result($f_id, $f_name);
   $query->execute();
}else{
  echo $db;
}
?>

Answer 1

You have to execute the query first before you use the bind_result()

<?php
session_start();
$db = new mysqli("localhost", "username", "password", "db_name") or
die("ERROR!!!");
$sql = "SELECT forum_id, forum_name FROM forum_tabl";
if($query = $db->prepare(sql)){
  $query->execute();
  $query = bind_result($f_id, $f_name);
}else{
  echo $db;
}
?>

Answer 2

A few things you should check / try-

1) Your server is up and running (apache or whatever server you are using)

2) Remote mysql has premission for the IP of the device that is trying to connect to the database

3) Add a "WHERE" clause to $sql = "SELECT forum_id, forum_name FROM forum_tabl";

eg : $sql = "SELECT forum_id, forum_name FROM forum_tabl WHERE something=?";

4) Check your variables - for instance in this line -

$sql = "SELECT forum_id, forum_name FROM forum_tabl";

forum_tabl might be forum_table

Other then that , here is a bit cleaner code for your purpose. Hope it works.

This is a config.php file which you can include to your other php pages that you need the use of the database:

<?php
    define('DB_SERVER', 'localhost');
    define('DB_USERNAME', 'your_username');
    define('DB_PASSWORD', 'your_password');
    define('DB_DATABASE', 'your_db');
    $db = mysqli_connect(DB_SERVER,DB_USERNAME,DB_PASSWORD,DB_DATABASE);
?>

Eventually , all other .php :

<?php
    include("config.php");
    $stmt = $db->prepare("SELECT forum_id, forum_name FROM forum_tabl WHERE something=?");
    $stmt->bind_param("s", $something);
    $stmt->execute();
    $result = $stmt->get_result();
    if($result->num_rows === 0) exit('No rows');
    while($row = $result->fetch_assoc()) 
    {
        $forum_id = row['forum_id'];
        .......
    }
?>

Hope this helps.