怎么用JAVA把Mysql数据库中的表的数据输出至文本文档中

首先导入 mysql-connector-java-5.1.45-bin.jar 包

代码如下：

import java.io.*;
import java.sql.*;

public class App {

    public static void main(String[] args) {
        
        try {
            
            Class.forName("com.mysql.jdbc.Driver");
            
            // 数据库用户
            String user = "root";
            
            // 数据库密码
            String password = "";
            
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_sale", user, password);
            
            Statement stmt = conn.createStatement();
            
            // 查询 , 从数据库 db_sale 的 product 表中查询 id, name, qty 字段
            ResultSet rs = stmt.executeQuery("SELECT id, name, qty FROM product");
            
            // 创建输出文件 result.txt
            File file = new File("d://result.txt");
            OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file));
            
            while (rs.next()) {
                
                writer.write(String.valueOf(rs.getLong(1)) + "\t");
                writer.write(rs.getString(2) + "\t");
                writer.write(String.valueOf(rs.getInt(3)));
                writer.write("\r\n");
                
                //System.out.println(rs.getLong(1));
                //System.out.println(rs.getString(2));
                //System.out.println(rs.getLong(3));
            }
            
            writer.flush();
            writer.close();
            
            rs.close();
            stmt.close();
            conn.close();
            
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

私信我，发给你

jdbc+io流