连接mysql数据库的代码

import pymysql

# 创建数据库连接
conn = pymysql.connect(host='数据库主机地址', port=3306, user='用户名', password='密码', database='数据库名', charset='utf8')

# 创建游标对象
cursor = conn.cursor()

# 执行SQL语句
sql = 'SELECT * FROM 表名'
cursor.execute(sql)

# 获取结果集
result = cursor.fetchall()

# 输出结果
for row in result:
    print(row)

# 关闭游标和连接
cursor.close()
conn.close()

import java.sql.*;

public class MySQLConnector {
    public static void main(String[] args) {
        // 数据库连接参数
        String url = "jdbc:mysql://数据库主机地址:3306/数据库名?useUnicode=true&characterEncoding=utf8";
        String user = "用户名";
        String password = "密码";

        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;

        try {
            // 加载数据库驱动
            Class.forName("com.mysql.jdbc.Driver");

            // 创建数据库连接
            conn = DriverManager.getConnection(url, user, password);

            // 创建Statement对象
            stmt = conn.createStatement();

            // 执行SQL查询
            String sql = "SELECT * FROM 表名";
            rs = stmt.executeQuery(sql);

            // 处理结果集
            while (rs.next()) {
                System.out.println(rs.getString("字段名"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            try {
                if (rs != null) rs.close();
                if (stmt != null) stmt.close();
                if (conn != null) conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

const mysql = require('mysql');

// 创建数据库连接配置
const connection = mysql.createConnection({
  host: '数据库主机地址',
  user: '用户名',
  password: '密码',
  database: '数据库名'
});

// 连接数据库
connection.connect();

// 执行SQL查询
const sql = 'SELECT * FROM 表名';
connection.query(sql, (error, results, fields) => {
  if (error) throw error;
  console.log(results);
});

// 关闭数据库连接
connection.end();