pdo连接mysql失败

# 检查是否安装了 pdo_mysql
php -m | grep pdo_mysql

# 对于 Ubuntu/Debian
sudo apt-get install php-pdo-mysql

# 对于 CentOS/RHEL
sudo yum install php-pdo-mysql

extension=pdo_mysql.so

try {
    $dsn = 'mysql:host=localhost;dbname=testdb;charset=utf8mb4';
    $user = 'username';
    $password = 'password';
    $pdo = new PDO($dsn, $user, $password);
} catch (PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}

# 对于 Ubuntu/Debian
sudo service mysql start

# 对于 CentOS/RHEL
sudo systemctl start mysqld

GRANT ALL PRIVILEGES ON testdb.* TO 'username'@'localhost';
FLUSH PRIVILEGES;

<?php
try {
    $dsn = 'mysql:host=localhost;dbname=testdb;charset=utf8mb4';
    $user = 'username';
    $password = 'password';
    $pdo = new PDO($dsn, $user, $password);
    echo "Connected successfully";
} catch (PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}
?>