纯Java实现控制台对数据库的增删改查（Eclipse）

1.实验环境Eclipse Mysql数据库 

新建数据库表

create database db_database01;

use db_database01;

create table students (ID int(11),Name varchar(25),Sex varchar(25),Age varchar(25));

整体框架图如下

    

    

2.新建3个包application放主文件，daos放数据层，users放用户封装。

具体代码如下：

（1）JDBCOperation.java

package com.hznu.qjc.application;

import java.util.Scanner;

import com.hznu.qjc.daos.DAO;

import com.hznu.qjc.users.Student;

public class JDBCOperation {
public static void main(String args[]) {
do{
System.out.println("++++++++++欢迎使用数据库增删改查功能++++++++++++");
System.out.println("+++1.insert 2.delete 3.update 4.query+++");
System.out.println("+++++++++++++请输入您选择的操作+++++++++++++++");
Scanner input = new Scanner(System.in);
int c = input.nextInt();
switch(c){
case 1: System.out.println("Insert");
       DAO.getAll();
           DAO.insert(new Student("Achilles", "Male", "14"));
           break; 
case 2: System.out.println("Delete"); 
       DAO.delete("Achilles");
           DAO.getAll();

                    break; 
case 3: System.out.println("Update");
       DAO.getAll();
       DAO.update(new Student("Bean", "", "7"));

                    break; 
case 4: System.out.println("Query"); 
       DAO.getAll();

                    break; 
   default: 
               System.out.println("consonant"); 
     }   
} while(true);
}

}

（2）DAO.java

package com.hznu.qjc.daos;

import com.hznu.qjc.users.*;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class DAO {
private static Connection getConn() {    
Connection conn = null;
try {
       Class.forName("com.mysql.jdbc.Driver"); //classLoader,加载对应驱动      
   } catch (ClassNotFoundException e) {
       e.printStackTrace();
   }
   String url = "jdbc:mysql://localhost:3306/db_database01";
   String username = "root";//数据库账户，一般为root
   String password = "";//数据库密码
   
   try{
       conn = DriverManager.getConnection(url, username, password);
   } catch (SQLException e) {
   e.printStackTrace();
   }
   return conn;
}

public static int insert(Student student) {
   Connection conn = getConn();
   int i = 0;
   String sql = "insert into students (Name,Sex,Age) values(?,?,?)";
   PreparedStatement pstmt;
   try {
       pstmt = (PreparedStatement) conn.prepareStatement(sql);
       pstmt.setString(1, student.getName());
       pstmt.setString(2, student.getSex());
       pstmt.setString(3, student.getAge());
       i = pstmt.executeUpdate();
       pstmt.close();
       conn.close();
   } catch (SQLException e) {
       e.printStackTrace();
   }
   return i;
}

public static int update(Student student) {
   Connection conn = getConn();
   int i = 0;
   String sql = "update students set Age='" + student.getAge() + "' where Name='" + student.getName() + "'";
   PreparedStatement pstmt;
   try {
       pstmt = (PreparedStatement) conn.prepareStatement(sql);
       i = pstmt.executeUpdate();
       System.out.println("resutl: " + i);
       pstmt.close();
       conn.close();
   } catch (SQLException e) {
       e.printStackTrace();
   }
   return i;
}

public static Integer getAll() {
   Connection conn = getConn();
   String sql = "select * from students";
   PreparedStatement pstmt;
   try {
       pstmt = (PreparedStatement)conn.prepareStatement(sql);
       ResultSet rs = pstmt.executeQuery();
       int col = rs.getMetaData().getColumnCount();
       System.out.println("============================");
       while (rs.next()) {
           for (int i = 1; i <= col; i++) {
               System.out.print(rs.getString(i) + "\t");
               if ((i == 2) && (rs.getString(i).length() < 8)) {
                   System.out.print("\t");
               }
            }
           System.out.println("");
       }
           System.out.println("============================");
   } ca
b4ed
tch (SQLException e) {
       e.printStackTrace();
   }
   return null;
}

public static int delete(String name) {
   Connection conn = getConn();
   int i = 0;
   String sql = "delete from students where Name='" + name + "'";
   PreparedStatement pstmt;
   try {
       pstmt = (PreparedStatement) conn.prepareStatement(sql);
       i = pstmt.executeUpdate();
       System.out.println("resutl: " + i);
       pstmt.close();
       conn.close();
   } catch (SQLException e) {
       e.printStackTrace();
   }
   return i;
}

}

（3）Student.java

package com.hznu.qjc.users;

public class Student {
protected String Id;
protected String Name;
protected String Sex;
protected String Age;

    public Student(String Name, String Sex, String Age) {

        this.Id = null; //default

        this.Name = Name;

        this.Sex = Sex;

        this.Age = Age;

    }

    public String getId() {

        return Id;

    }

    public void setId(String Id) {

        this.Id = Id;

    }

    public String getName() {

        return Name;

    }

    public void setName(String Name) {

        this.Name = Name;

    }

    public String getSex() {

        return Sex;

    }

    public void setSex(String Sex) {

        this.Sex = Sex;

    }

    public String getAge() {

        return Age;

    }

    public void setage(String Age) {

        this.Age = Age;

    }

        

}

3.实验结果如下