菁英科技（卓目鸟学苑）- 专注软件测试菁英教育

标题: java-homework [打印本页]

作者: 5269 时间: 2021-3-15 19:51
标题: java-homework
package equ.utils;

import equ.model.Equ;

import java.sql.*;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

/*
操作sqlite数据库，实现对数据库的增删改查功能。
JDBC Mysql、sqlite有对对应的jar,maven的官网下载
*/

public class SqliteDb {
//连接数据库
private Connection connect(){
      //jdbc:subprotocol:subname
      //ddbc:数据库类型：数据库相对于工程的路径
      String url = "jdbc:sqlite:src/equ/db/equ.db";
      try{
         //加载类
         Class.forName("org.sqlite.JDBC");
         //连接数据库
         Connection conn = DriverManager.getConnection(url);
         System.out.println("连接数据库成功");
         return conn;
      }catch (ClassNotFoundException | SQLException e){
         System.out.println("连接数据库异常，异常信息为："+e.getMessage());
      }
      return null;
}
//断开数据库连接
private void disconnect(Connection conn){
      try{
         conn.close();
      }catch(SQLException e){
         System.out.println("断开数据库异常，异常信息为："+e.getMessage());
      }
}

//执行sql语句,执行插入、删除、更新类的操作，返回true/false
private boolean executeUpdate(Connection conn,String sql){
      //Statement 是执行sql语句的接口
      Statement statement = null;
      try{
         statement = conn.createStatement();
         int count = statement.executeUpdate(sql);
         System.out.println("执行sql语句成功，影响"+count+"条数据");
         statement.close();
         return count >= 1;
      }catch (SQLException e){
         System.out.println("执行sql语句异常，异常信息为："+e.getMessage());
      }
      return false;
}
//执行sql语句，执行查询类的操作，返回查询的结果
private List<Equ> executeQuery(Connection conn, String sql){
      List<Equ> equs = new ArrayList<>();
      Statement statement = null;
      try{
         statement = conn.createStatement();
         ResultSet rs = statement.executeQuery(sql);
         if(rs != null){//查询结果不为空
            while (rs.next()){
                  //根据列名获取每一列的值
                  String id = rs.getString("id");
                  String name = rs.getString("name");
                  String location = rs.getString("location");
                  String baoFei = rs.getString("baoFei");
                  String buyTime = rs.getString("buyTime");
                  String baoFeiTime = rs.getString("baoFeiTime");
                  String record = rs.getString("record");
                  //根据获取的信息构造Equ对象
                  Equ equ = new Equ(id,name,location,baoFei,baoFeiTime,buyTime,record);
                  equs.add(equ);
            }
            System.out.println("执行sql语句，查询到"+equs.size()+"条语句");
         }
      }catch (SQLException e){
         System.out.println("执行sql语句异常，异常信息为："+e.getMessage());
      }
      return equs;
}

欢迎光临菁英科技（卓目鸟学苑）- 专注软件测试菁英教育 (http://www.zmnxy.com/)