java连接数据库并显示数据

深碍√TFBOYSˉ_ 2022-07-11 13:19 221阅读 0赞

1. 导入jdbc包

java要连接MySQL数据库需要用到JDBC工具(mysql-connector-java-5.1.39-bin.jar)，这是一个jar包，不同的数据库对应不同的jar包，这里用的是MySQL数据库jar包，导入很简单，鼠标对项目右击 - Build Path - Configure Build Path - 右侧选Libraries - Add External JARs,选择正确的jdbc包就行了。

2. 创建数据库(示例: 数据库名studentdb , 表名stable)

![20170129200044009][]

3 新建属性及构造方法类(stuInfo.java)

public class stuInfo {
    	private int sno;
    	private String sname;
    	private String sex;
    	private int age;
    	
    	public int getSno() {
    		return sno;
    	}
    	public void setSno(int sno) {
    		this.sno = sno;
    	}
    	public String getSname() {
    		return sname;
    	}
    	public void setSname(String sname) {
    		this.sname = sname;
    	}
    	public String getSex() {
    		return sex;
    	}
    	public void setSex(String sex) {
    		this.sex = sex;
    	}
    	public int getAge() {
    		return age;
    	}
    	public void setAge(int age) {
    		this.age = age;
    	}
    	
    	public stuInfo(){
    		
    	}
    	public stuInfo(int sno, String sname, String sex, int age) {
    		this.sno = sno;
    		this.sname = sname;
    		this.sex = sex;
    		this.age = age;
    	}
    }

3. 新建主类(shoeTest.java)

import info.stuInfo;
    
    import java.util.ArrayList;
    import java.sql.*;
    
    public class showTest {
    
    	
    	public static void main(String[] args) {
    		ArrayList<stuInfo> list = getAllStus();
    		
    		if(list.size() == 0){
    			System.out.println("暂无数据");
    		}else{
    			for(stuInfo s: list){  //遍历集合数据
    				System.out.println(s.getSno()+"\t"+s.getSname()+"\t"+s.getSex()+"\t"+s.getAge());
    			}
    		}
    
    	}
    	
    	//采用集合的方法，返回数据集合
    	public static ArrayList<stuInfo> getAllStus(){
    		ArrayList<stuInfo> stulist = new ArrayList<stuInfo>();
    		
    		String url = "com.mysql.jdbc.Driver"; //加载驱动包
    		String connectSql = "jdbc:mysql://127.0.0.1:3306/studentdb"; //链接MySQL数据库
    		String sqlUser = "root"; //数据库账号
    		String sqlPasswd = "*****"; //你的数据库密码
    		
    		Connection con = null;
    		PreparedStatement psm = null;
    		ResultSet rs = null;
    		
    		
    		try {
    			//加载驱动包
    			Class.forName(url);
    			//连接MYSQL
    			con = DriverManager.getConnection(connectSql,sqlUser,sqlPasswd);
    			//执行MYSQL语句
    			psm = con.prepareStatement("select * from stable");
    		    rs = psm.executeQuery();
    			System.out.println("编号"+"\t"+"姓名"+"\t"+"性别"+"\t"+"年龄");
    			while(rs.next()){
    				stuInfo s = new stuInfo();
    				s.setSno(rs.getInt(1));
    				s.setSname(rs.getString(2));
    				s.setSex(rs.getString(3));
    				s.setAge(rs.getInt(4));
    				
    				stulist.add(s);	
    			}
    			
    			//关闭数据库连接
    			rs.close();
    			psm.close();
    			con.close();
    			
    		} catch (Exception e) {
    			System.out.println("显示所有数据报错，原因："+e.getMessage());
    		}
    		
    		return stulist;	
    	}
    	
    
    }

4. 运行测试  
![20170129200817359][]

[20170129200044009]: /images/20220711/16227eb50e3b4080a6ee7f6f7e5a3acf.png
[20170129200817359]: /images/20220711/033b6abacfb0400a9fb0679bb6e3f001.png