連接我的MySQL數據庫在PHP

Question

我有我的PHP這樣的代碼來連接我的服務器數據庫

<?php 
    $con=mysqli_connect("","username" ,"password","databasename"); 
    if (mysqli_connect_errno()) 
    { 
     echo "Failed to connect to MySQL: " . mysqli_connect_error(); 
    } 
    ?> 

但它顯示爲「無法連接到MySQL」，什麼是錯的驗證碼？我第一次我試圖在Web服務器上，而我的本地主機工作完美。任何人都有一些建議？

Answer 1

mysqli_connect("","username" ,"password","databasename");//Server name cannot be NULL

使用loaclhost服務器名（在Loacl）

<?php 
    $con = mysqli_connect("localhost","username" ,"password","databasename"); 

    if (mysqli_connect_errno()) 
    { 
     echo "Failed to connect to MySQL: " . mysqli_connect_error(); 
    } 
?> 

或者可以使用庫MySQLi程序

<?php 
    $servername = "localhost"; 
    $username = "username"; 
    $password = "password"; 

    // Create connection 
    $con = mysqli_connect($servername, $username, $password); 

    // Check connection 
    if (!$con) { 
     die("Connection failed: " . mysqli_connect_error()); 
    } 
    echo "Connected successfully"; 
?> 

編輯01

$servername = "localhost"; 
$username = "root"; 
$password = ""; 

Answer 2

應指定主機名

$con = mysqli_connect("localhost","username" ,"password","databasename"); 

如果它返回象

無法連接到MySQL的錯誤：無法通過套接字連接到本地MySQL服務器「的/ var/lib中/ MySQL的/mysql.sock'

將localhost替換爲127.0.0.1。

如果仍然無法連接檢查是否mysql服務器實際運行。

service mysqld start 

然後，嘗試下面的一個下列：

（MySQL的，如果你沒有設置密碼）

mysql -u root 

如果你已經設置密碼

mysql -u root -p 

Answer 3

爲什麼使用mysqli？只需使用PDO更安全的MySQL連接只需使用：

$hostname='localhost'; 
$username='root'; 
$password=''; 

try { 
    $dbh = new PDO("mysql:host=$hostname;dbname=dbname",$username,$password); 
} 
catch(PDOException $e) { 
echo $e->getMessage(); 
} 

Answer 4

我soved這傢伙，現在是通過使用

$con=mysqli_connect("current_server_IP","username" ,"password","databasename"); 

工作現在我已經能夠連接登錄。謝謝你們的幫助！

Answer 5

$localhost = "localhost"; 
    $root = "root"; 
    $password = ""; 
    $con = mysql_connect($localhost,$root,$password) or die('Could not connect to database'); 
    mysql_select_db("db_name",$con);