SpringBoot整合JDBC数据库操作-6:实现查询数据操作

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