MySQL数据库连接的代码

import java.sql.*;

public class MySQLExample {
    public static void main(String[] args) {
        try {
            // 加载MySQL驱动
            Class.forName("com.mysql.jdbc.Driver");
            
            // 创建数据库连接
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "username", "password");
            
            // 创建查询语句
            Statement stmt = conn.createStatement();
            String sql = "SELECT * FROM mytable";
            
            // 执行查询
            ResultSet rs = stmt.executeQuery(sql);
            
            // 处理查询结果
            while (rs.next()) {
                String column1 = rs.getString("column1");
                int column2 = rs.getInt("column2");
                // 其他操作...
            }
            
            // 关闭连接
            rs.close();
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

import mysql.connector

# 创建数据库连接
conn = mysql.connector.connect(
    host="localhost",
    user="username",
    password="password",
    database="mydatabase"
)

# 创建查询语句
cursor = conn.cursor()
sql = "SELECT * FROM mytable"

# 执行查询
cursor.execute(sql)

# 处理查询结果
for row in cursor.fetchall():
    column1 = row[0]
    column2 = row[1]
    # 其他操作...

# 关闭连接
cursor.close()
conn.close()

using System;
using MySql.Data.MySqlClient;

public class MySQLExample {
    public static void Main(string[] args) {
        string connectionString = "Server=localhost;Database=mydatabase;Uid=username;Pwd=password;";
        
        // 创建数据库连接
        MySqlConnection conn = new MySqlConnection(connectionString);
        
        try {
            // 打开连接
            conn.Open();
            
            // 创建查询语句
            string sql = "SELECT * FROM mytable";
            
            // 执行查询
            MySqlCommand cmd = new MySqlCommand(sql, conn);
            MySqlDataReader reader = cmd.ExecuteReader();
            
            // 处理查询结果
            while (reader.Read()) {
                string column1 = reader.GetString(0);
                int column2 = reader.GetInt32(1);
                // 其他操作...
            }
            
            // 关闭连接
            reader.Close();
            conn.Close();
        } catch (Exception e) {
            Console.WriteLine(e.ToString());
        }
    }
}