服务器上连接mysql数据库

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

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检测连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
} 
echo "连接成功";
?>

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="username",
  password="password",
  database="database"
)

print(mydb)

import java.sql.*;

public class ConnectMySQL {
    public static void main(String[] args) {
        Connection conn = null;
        try {
            // 数据库连接参数
            String url = "jdbc:mysql://localhost/database";
            String username = "username";
            String password = "password";

            // 创建连接
            conn = DriverManager.getConnection(url, username, password);

            // 执行查询或操作

            // 关闭连接
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}