用java连接mysql数据库实现对MySQL建表语句用户表users包括id，username，年龄，所在年级，所属系部，专业的增删改查，其中改和删要在控制台实现

这里提供一个简单的示例代码：

import java.sql.*;

public class MySQLDemo {
    // 数据库连接参数
    private static final String URL = "jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC";
    private static final String USER = "root";
    private static final String PASSWORD = "123456";

    public static void main(String[] args) {
        Connection conn = null;
        try {
            // 1. 加载驱动程序
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2. 获取数据库连接
            conn = DriverManager.getConnection(URL, USER, PASSWORD);

            // 3. 创建Statement对象
            Statement stmt = conn.createStatement();

            // 4. 执行建表语句
            String sql = "CREATE TABLE users ("
                    + "id INT NOT NULL AUTO_INCREMENT,"
                    + "username VARCHAR(50) NOT NULL,"
                    + "age INT,"
                    + "grade VARCHAR(50),"
                    + "department VARCHAR(50),"
                    + "major VARCHAR(50),"
                    + "PRIMARY KEY (id))";
            stmt.executeUpdate(sql);

            // 5. 插入数据
            sql = "INSERT INTO users (username, age, grade, department, major) VALUES "
                    + "('张三', 20, '大一', '计算机科学与技术系', '软件工程'),"
                    + "('李四', 21, '大二', '信息管理系', '信息管理与信息系统')";
            stmt.executeUpdate(sql);

            // 6. 查询数据
            sql = "SELECT * FROM users";
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                int id = rs.getInt("id");
                String username = rs.getString("username");
                int age = rs.getInt("age");
                String grade = rs.getString("grade");
                String department = rs.getString("department");
                String major = rs.getString("major");
                System.out.println(String.format("%d\t%s\t%d\t%s\t%s\t%s", id, username, age, grade, department, major));
            }

            // 7. 更新数据
            sql = "UPDATE users SET age = 22 WHERE id = 1";
            stmt.executeUpdate(sql);
            System.out.println("更新后的数据：");
            rs = stmt.executeQuery("SELECT * FROM users WHERE id = 1");
            while (rs.next()) {
                int id = rs.getInt("id");
                String username = rs.getString("username");
                int age = rs.getInt("age");
                String grade = rs.getString("grade");
                String department = rs.getString("department");
                String major = rs.getString("major");
                System.out.println(String.format("%d\t%s\t%d\t%s\t%s\t%s", id, username, age, grade, department, major));
            }

            // 8. 删除数据
            System.out.println("删除数据(id=2)：");
            sql = "DELETE FROM users WHERE id = 2";
            stmt.executeUpdate(sql);
            rs = stmt.executeQuery("SELECT * FROM users");
            while (rs.next()) {
                int id = rs.getInt("id");
                String username = rs.getString("username");
                int age = rs.getInt("age");
                String grade = rs.getString("grade");
                String department = rs.getString("department");
                String major = rs.getString("major");
                System.out.println(String.format("%d\t%s\t%d\t%s\t%s\t%s", id, username, age, grade, department, major));
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                // 9. 关闭数据库连接
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

注：这里使用的 MySQL 版本为 8.0.23。如果版本不同，可能需要修改连接参数。