SpringBoot整合JDBC数据库操作第六弹-实现查询数据操

上篇文章我们讲到了怎么对批量操作(批量增加,批量修改,批量删除),这篇文章主要讲解一下对数据的查询操作.

• 修改ArticleRepository类文件, 增加查询数据方法

  /**
   * 查询所有数据
   */
  public List<Article> findAll() {
      String sql = "SELECT id, title, description FROM article";
      return jdbcTemplate.query(sql, new RowMapper<Article>() {
          @Override
          public Article mapRow(ResultSet resultSet, int i) throws SQLException {
              Article article = new Article();
              article.setId(resultSet.getInt("id"));
              article.setTitle(resultSet.getString("title"));
              article.setDescription(resultSet.getString("description"));
              return article;
          }
      });
  }
   
  /**
   * 查询单条数据
   */
  public Article findById(Integer id) {
      String sql = "SELECT id, title, description FROM article WHERE id = ?";
      return jdbcTemplate.queryForObject(sql, new Object[]{id}, new RowMapper<Article>() {
          @Override
          public Article mapRow(ResultSet resultSet, int i) throws SQLException {
              Article article = new Article();
              article.setId(resultSet.getInt("id"));
              article.setTitle(resultSet.getString("title"));
              article.setDescription(resultSet.getString("description"));
              return article;
          }
      });
  }
  

• 修改ArticleService类文件, 增加查询数据方法

  List<Article> findAll();
   
  Article findById(Integer id);
  

• 修改ArticleServiceImpl类文件, 增加查询数据方法

  @Override
  public List<Article> findAll() {
      return articleRepository.findAll();
  }
   
  @Override
  public Article findById(Integer id) {
      return articleRepository.findById(id);
  }
  

• 修改API接口层ArticleController, 增加查询数据对外接口

  @RequestMapping(value = "list", method = RequestMethod.GET)
  List<Article> list() {
      return articleService.findAll();
  }
   
  @RequestMapping(value = "info", method = RequestMethod.GET)
  Article info(@RequestParam Integer id) {
      return articleService.findById(id);
  }
  

• 使用RestAPI测试工具测试api接口可用性