java mysql对学生信息表进行操作

1、JDBC单表记录的增删改查（20分）

已知：建立表student，并向表里插入几条记录，

create table student(

id int PRIMARY KEY auto_increment,

name varchar(20) not null,

schoolin date not null,

score float not null);

insert into student values(null,’李丽’,’2015-09-01’,86);

insert into student values(null,’王五’,’2016-09-01’,99);

insert into student values(null,’张三’,’2014-09-01’,88);

 

要求：用JAVA程序实现如下功能：

1、向表中增加记录并显示所有记录（数据自己指定）；

2、从表中删除id=1的记录并显示所有记录；

3、修改表中记录：查询条件id=2，将name修改为：山东理工，修改完毕显示所有记录；

4、查询表中id=3的记录并显示；

Student类

public class Student {
	int id;
	String name, schoolin;
	float score;
	
	public Student() {
		super();
	}

	public Student(int id, String name, String schoolin, float score) {
		super();
		this.id = id;
		this.name = name;
		this.schoolin = schoolin;
		this.score = score;
	}
	
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", schoolin=" + schoolin + ", score=" + score + "]";
	}
	
	
	

}

BaseDao类

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class BaseDao {
	Connection con;
	PreparedStatement pst;
	ResultSet rs;

	public Connection getConn() throws ClassNotFoundException, SQLException {
		// 1 加载驱动
		Class.forName("com.mysql.jdbc.Driver");
		// 2 获得数据库的连接
		Connection con = DriverManager.getConnection(
				"jdbc:mysql://localhost:3307/Student?useUnicode=true&characterEncoding=utf-8", "root", "usbw");
		return con;
	}

	public void closeAll() throws SQLException {
		if (rs != null) {
			rs.close();
		}
		if (pst != null) {
			pst.close();
		}
		if (con != null) {
			con.close();
		}
	}
}

StudentDao类

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class StudentDao extends BaseDao {
	public int addStu(Student st) {
		int rst = 0;
		try {
			con = getConn();
			String sql_insert = "insert into student(id, name, schoolin, score) values(null, ?, ?, ?)";
			PreparedStatement pst = con.prepareStatement(sql_insert);
			pst.setString(1, st.name);
			pst.setString(2, st.schoolin);
			pst.setFloat(3, st.score);
			rst = pst.executeUpdate();
			
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		try {
			closeAll();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return rst;
	}

	public int deleteStu(int id) throws ClassNotFoundException, SQLException {
		con = getConn();
		String sql = "delete from student where id=?";
		PreparedStatement pst = con.prepareStatement(sql);
		pst = con.prepareStatement(sql);
		pst.setInt(1, id);

		int result = pst.executeUpdate();
		closeAll();
		return result;
	}

	public int updateStu(int id1, String name)  {
		
		int age;
		String sql;
		int rst = 0;

		sql = "update student set name = ? where id = ?";
		PreparedStatement pst;
		try {
			con = getConn();
			pst = con.prepareStatement(sql);
			pst.setString(1, name);
			pst.setInt(2, id1);
			rst = pst.executeUpdate();
			closeAll();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		return rst;
	}

	public List<Student> queryAll() throws SQLException, ClassNotFoundException {
		con = getConn();
		List<Student> stu = new ArrayList<Student>();
		String sql = "select * from student";
		PreparedStatement pst = con.prepareStatement(sql);
		ResultSet rst = pst.executeQuery();
		while (rst.next()) {
			int id = rst.getInt(1);
			String name = rst.getString(2);
			String time = rst.getString(3);
			float score = rst.getFloat(4);
			stu.add(new Student(id, name, time, score));
			// System.out.println(id + "---" + name + "---" + age);
		}
		closeAll();
		return stu;
	}

	public void queryById(int id)  {
		try {
			con = getConn();
			String sql = "select name, schoolin, score from student where id=?";
			PreparedStatement pst = con.prepareStatement(sql);
			pst.setInt(1, id);
			ResultSet rst = pst.executeQuery();
			if (rst.next() != false) {
				String name = rst.getString("name");
				String time = rst.getString("schoolin");
				float score = rst.getFloat("score");
				Student temp = new Student(id, name, time, score);
				System.out.println(temp);
			}
			closeAll();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}

}

TestStudent类

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class TestStudent {

	public static void main(String[] args) throws ClassNotFoundException, SQLException {
		StudentDao st = new StudentDao();
		Student s1 = new Student(1, "abc", "2016-12-12", 99);
		Student s2 = new Student(1, "123", "2010-5-12", 60);
		int rst = st.addStu(s1);
		if(rst == 1) {
			System.out.println("add success!");
		}
		rst = st.addStu(s2);
		if(rst == 1) {
			System.out.println("add success!");
		}
		
		List<Student> stu = new ArrayList<Student>();
		stu = st.queryAll();
		for(Student st1: stu) {
			System.out.println(st1.toString());
		}
		
		String name = "山东理工";
		st.updateStu(2, name);
		
		List<Student> stu1 = new ArrayList<Student>();
		stu = st.queryAll();
		for(Student st1: stu) {
			System.out.println(st1.toString());
		}
		
		st.queryById(3);
	}

}