以下是一个简单的JDBC查询数据库的代码示例：
云服务器
物理服务器
虚拟主机
跨境电商服务器import java.sql.*;
public class JdbcQueryExample {
????public?static?void?main(String[]?args)?{
????????//?JDBC连接信息
????????String?url?=?“jdbc:mysql://localhost:3306/mydatabase”;
????????String?username?=?“root”;
????????String?password?=?“password”;
????????
????????//?SQL查询语句
????????String?query?=?“SELECT?*?FROM?mytable”;
????????
????????try?{
????????????//?加载JDBC驱动程序
????????????Class.forName(“com.mysql.jdbc.Driver”);
????????????
????????????//?建立数据库连接
????????????Connection?connection?=?DriverManager.getConnection(url,?username,?password);
????????????
????????????//?创建Statement对象
????????????Statement?statement?=?connection.createStatement();
????????????
????????????//?执行查询
????????????ResultSet?resultSet?=?statement.executeQuery(query);
????????????
????????????//?处理查询结果
????????????while?(resultSet.next())?{
????????????????int?id?=?resultSet.getInt(“id”);
????????????????String?name?=?resultSet.getString(“name”);
????????????????int?age?=?resultSet.getInt(“age”);
????????????????System.out.println(id?+?",?"?+?name?+?",?"?+?age);
????????????}
????????????
????????????//?关闭结果集、Statement和连接
????????????resultSet.close();
????????????statement.close();
????????????connection.close();
????????}?catch?(ClassNotFoundException?|?SQLException?e)?{
????????????e.printStackTrace();
????????}
????}
}
这个例子假设你已经安装并配置了MySQL数据库，并且在本地主机上运行。可以根据实际情况修改连接URL、用户名和密码。查询语句可以根据你的表结构修改。
辰迅云「云服务器」，即开即用、新一代英特尔至强铂金CPU、三副本存储NVMe SSD云盘，价格低至29元/月。点击查看>>
推荐阅读： websocket数据库数据推送怎么实现