MySQL數(shù)據(jù)庫是一款常用的關(guān)系型數(shù)據(jù)庫管理系統(tǒng)。在使用MySQL數(shù)據(jù)庫時(shí)，我們常常遇到連接失敗的情況。這里介紹幾種可能導(dǎo)致連接失敗的原因及對應(yīng)解決方案。

1. 用戶名或密碼錯(cuò)誤

// PHP連接MySQL
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "test";
// 創(chuàng)建連接
$conn = new mysqli($servername, $username, $password, $dbname);
// 檢測連接
if ($conn->connect_error) {
die("連接失敗: " . $conn->connect_error);
}

解決方案：檢查用戶名和密碼是否正確，或者嘗試重置密碼

2. MySQL服務(wù)未啟動(dòng)

// PHP連接MySQL
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "test";
// 創(chuàng)建連接
$conn = new mysqli($servername, $username, $password, $dbname);
// 檢測連接
if ($conn->connect_error) {
die("連接失敗: " . $conn->connect_error);
}

解決方案：啟動(dòng)MySQL服務(wù)

3. 防火墻阻止連接

// PHP連接MySQL
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "test";
// 創(chuàng)建連接
$conn = new mysqli($servername, $username, $password, $dbname);
// 檢測連接
if ($conn->connect_error) {
die("連接失敗: " . $conn->connect_error);
}

解決方案：檢查防火墻設(shè)置，允許MySQL端口的訪問

4. MySQL配置文件錯(cuò)誤

// PHP連接MySQL
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "test";
// 創(chuàng)建連接
$conn = new mysqli($servername, $username, $password, $dbname);
// 檢測連接
if ($conn->connect_error) {
die("連接失敗: " . $conn->connect_error);
}

解決方案：檢查MySQL配置文件，修正錯(cuò)誤設(shè)置