java连接数据库实现增删改查代码

你好！下面是 Java 连接数据库实现增删改查的代码示例：

import java.sql.*;

public class Demo {
    // JDBC 驱动名和数据库 URL
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost:3306/db_name?useUnicode=true&characterEncoding=utf-8&useSSL=false";

    // 数据库的用户名与密码
    static final String USER = "user";
    static final String PASS = "password";

    public static void main(String[] args) throws SQLException {
        Connection conn = null;
        Statement stmt = null;

        try {
            // 注册 JDBC 驱动
            Class.forName(JDBC_DRIVER);

            // 打开链接
            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            // 执行查询
            stmt = conn.createStatement();
            String sql = "SELECT * FROM employee";
            ResultSet rs = stmt.executeQuery(sql);

            // 处理结果集
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int age = rs.getInt("age");
                System.out.println("ID: " + id + "\tName: " + name + "\tAge: " + age);
            }

            // 关闭资源
            rs.close();
            stmt.close();
            conn.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (stmt != null) stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }

            try {
                if (conn != null) conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

上述代码演示了如何连接 MySQL 数据库并执行查询语句。如果需要实现新增、修改、删除等操作，只需要修改 SQL 语句即可。希望能对你有所帮助。