使用java编写程序实现创建一学生数据库School，创建一表studb，包含字段：学号、姓名、性别、专业、入学年份。编写程序对studb表进行学生信息的增、删、改、查操作

好的，这是一个比较常见的数据库操作，以下是Java代码示例，需要使用 JDBC 连接数据库：

1. 导入 JDBC 驱动包

Class.forName("com.mysql.jdbc.Driver");

2. 建立数据库连接

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/School", "root", "password");

3. 创建 SQL 语句并执行

- 增加学生信息

String sql = "INSERT INTO studb (id, name, gender, major, enrollment_year) VALUES (?, ?, ?, ?, ?)";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "1001");
pstmt.setString(2, "张三");
pstmt.setString(3, "男");
pstmt.setString(4, "计算机科学");
pstmt.setString(5, "2020");
int result = pstmt.executeUpdate();
if (result > 0) {
    System.out.println("学生信息添加成功！");
}

- 删除学生信息

String sql = "DELETE FROM studb WHERE id = ?";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "1001");
int result = pstmt.executeUpdate();
if (result > 0) {
    System.out.println("学号为 1001 的学生信息删除成功！");
}

- 修改学生信息

String sql = "UPDATE studb SET name = ?, gender = ?, major = ?, enrollment_year = ? WHERE id = ?";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "李四");
pstmt.setString(2, "女");
pstmt.setString(3, "软件工程");
pstmt.setString(4, "2019");
pstmt.setString(5, "1002");
int result = pstmt.executeUpdate();
if (result > 0) {
    System.out.println("学生信息修改成功！");
}

- 查询学生信息

String sql = "SELECT * FROM studb WHERE id = ?";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "1002");
ResultSet rs = pstmt.executeQuery();
while(rs.next()) {
    System.out.println("学号：" + rs.getString("id") + 
                       ", 姓名：" + rs.getString("name") + 
                       ", 性别：" + rs.getString("gender") + 
                       ", 专业：" + rs.getString("major") + 
                       ", 入学年份：" + rs.getString("enrollment_year"));
}

完整代码如下：

import java.sql.*;

public class StudentDatabase {
    public static void main(String[] args) {
        Connection conn = null;
        try {
            // 1. 加载 JDBC 驱动
            Class.forName("com.mysql.jdbc.Driver");
            // 2. 建立数据库连接
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/School", "root", "password");

            // 增加学生信息
            String sql = "INSERT INTO studb (id, name, gender, major, enrollment_year) VALUES (?, ?, ?, ?, ?)";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "1001");
            pstmt.setString(2, "张三");
            pstmt.setString(3, "男");
            pstmt.setString(4, "计算机科学");
            pstmt.setString(5, "2020");
            int result = pstmt.executeUpdate();
            if (result > 0) {
                System.out.println("学生信息添加成功！");
            }

            // 删除学生信息
            sql = "DELETE FROM studb WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "1001");
            result = pstmt.executeUpdate();
            if (result > 0) {
                System.out.println("学号为 1001 的学生信息删除成功！");
            }

            // 修改学生信息
            sql = "UPDATE studb SET name = ?, gender = ?, major = ?, enrollment_year = ? WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "李四");
            pstmt.setString(2, "女");
            pstmt.setString(3, "软件工程");
            pstmt.setString(4, "2019");
            pstmt.setString(5, "1002");
            result = pstmt.executeUpdate();
            if (result > 0) {
                System.out.println("学生信息修改成功！");
            }

            // 查询学生信息
            sql = "SELECT * FROM studb WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "1002");
            ResultSet rs = pstmt.executeQuery();
            while(rs.next()) {
                System.out.println("学号：" + rs.getString("id") + 
                                   ", 姓名：" + rs.getString("name") + 
                                   ", 性别：" + rs.getString("gender") + 
                                   ", 专业：" + rs.getString("major") + 
                                   ", 入学年份：" + rs.getString("enrollment_year"));
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

注意，这里的 `jdbc:mysql://localhost:3306/School` 需要替换成你自己的 MySQL 数据库地址，以及 `root` 和 `password` 需要替换成你自己的 MySQL 数据库的用户名和密码。此外，你需要在 MySQL 中创建一个名为 `School` 的数据库，并在其中创建一个名为 `studb` 的表，包含字段：`id`、`name`、`gender`、`major`、`enrollment_year`。