選擇所有帖子及其類別和標簽以顯示在主頁上

Question

我想選擇所有帖子及其類別和標簽以顯示在主頁上，我還想選擇其他查詢中單個帖子的所有類別和標簽以顯示在帖子頁面上，此時我已經完成了，但是我我在 foreach 中使用 3 個查詢來獲取所有數據，但我認為它是冗余的，我想知道是否可以在單個查詢中獲取所有數據，這是我的表的簡化示例：

帖子

| id_post | title_post    | created_at          |
+---------+---------------+---------------------+
|       1 | Post Title  1 | 2019-11-26 06:40:03 |
|       2 | Post Title  2 | 2019-11-26 06:40:03 |
|       3 | Post Title  3 | 2019-11-26 06:40:03 |
+---------+---------------+---------------------+

POST_CATEGORIES

+---------+-------------+
| post_id | category_id |
+---------+-------------+
|       1 |           1 |
|       1 |           2 |
|       1 |           3 |
|       2 |           2 |
|       3 |           1 |
|       3 |           3 |
+---------+-------------+

類別

+--------+----------------+
| id_cat | title_category |
+--------+----------------+
|      1 | Cat Name 1     |
|      2 | Cat Name 2     |
|      3 | Cat Name 3     |
+--------+----------------+

POST_TAGS

+---------+-----------+
| post_id | tag_id    |
+---------+-----------+
|       1 |         1 |
|       1 |         2 |
|       1 |         3 |
|       2 |         4 |
|       2 |         5 |
|       2 |         6 |
|       3 |         6 |
+---------+-----------+

標簽

+--------+-------------+
| id_tag | tag_title   |
+--------+-------------+
|      1 | TagName1    |
|      2 | TagName2    |
|      3 | TagName3    |
|      4 | TagName4    |
|      5 | TagName5    |
|      6 | TagName6    |
+--------+-------------+

所以為了在主頁面上顯示我使用這個：

$sql = "SELECT * FROM posts WHERE active_post = 1 ORDER BY id_post $mode LIMIT $base, $max";

 <?php foreach ($posts as $key => $value) : ?>
  <article class="col-12 post">
    <div class="post__header py-4 px-0">
      <h2 class="font-weight-bold post__title">
        <a href="<?php echo $blog['domain'] . $value['url_post'] ?>"><?php echo $value['title_post'] ?></a>
      </h2>
      <div class="post__info">
        <ul class="mb-0 text-muted">
          <li>
            <span class="text-muted">
              <i class="far fa-calendar-alt icon"></i>
              <?php echo $value['created_at'] ?>
            </span>
          </li>
          <li>
            <span class="text-muted">
              <i class="far fa-folder icon"></i>
            </span>
            <?php

              $cat = BlogController::getCategories($value['id_post']);
              $c = '';
              if (!empty($cat)) {
                foreach ($cat as $k => $val) {
                  $c .= '<a class="text-muted" href="' . $blog['domain'] . 'category/' . $val["url_category"] . '">' . $val["title_category"] . '</a>, ';
                }
                echo substr($c, 0, -2);
              } else {
                echo '<a class="text-muted" href="not-category">Not Category</a>';
              }
              ?>
          </li>
          <li>
            <?php
              $tags = BlogController::getTags(null, $value['id_post']);
              $t = '';
              if (!empty($tags)) {
                foreach ($tags as $key => $val) {
                  $t .= '<a class="text-muted" href="' . $blog['domain'] . 'tags/' . $val["url_tags"] . '">' . $val["title_tag"] . '</a>, ';
                }
                echo '<span class="text-muted">
                        <i class="fas fa-hashtag icon"></i>
                      </span>';
                echo substr($t, 0, -2);
              }
              ?>
          </li>
        </ul>
      </div>
    </div>
    <figure class="mb-0">
      <img src="<?php echo $blog['domain'] . substr($value['img_post'], 22); ?>" alt="<?php echo $value['title_post'] ?>" class="img-fluid post__image" loading="lazy" />
    </figure>
    <div class="post__body">
      <p class="post__text">
        <?php echo $value['desc_post'] ?>
      </p>
      <a href="<?php echo  $blog['domain'] . $value['url_post'] ?>" class="post__link color-link">Read more... <span>→</span></a>
    </div>
  </article>
<?php endforeach; ?>

BlogController 將信息發送到 BlogModel 並針對類別和標簽執行此查詢：

$sql = "SELECT p.post_id, cat.title_category FROM post_categories as p INNER JOIN categories as cat ON p.category_id = cat.id_cat WHERE p.post_id = :id";

$sql = "SELECT p.post_id, tag.title_tag FROM post_tags as p INNER JOIN tags as tag ON p.tag_id = tag.id_tag WHERE p.post_id = :id";

所以我想做一個查詢來獲取我嘗試這樣做的所有信息：

$sql = "SELECT p.id_post, p.title_post, p.created_at, cat.title_category, tag.title_tag FROM posts as p INNER JOIN post_categories AS pc INNER JOIN categories AS cat INNER JOIN tags as tag INNER JOIN post_tags AS pt ON pc.post_id = p.id_post WHERE pc.category_id = cat.id_cat AND pt.post_id = tag.id_tag LIMIT 0, 10";

以下是結果（結果僅限於 10 個只是為了不打印大數據）：

+---------+---------------+---------------------+------------------+-----------------+
| id_post | title_post    | created_at         | title_category   | title_tag       |
+---------+---------------+---------------------+------------------+-----------------+
|       1 | Title Post 1 | 2019-11-26 06:40:03 | Cat Name 1       | TagName1        |
|       1 | Title Post 1 | 2019-11-26 06:40:03 | Cat Name 2       | TagName1        |
|       1 | Title Post 1 | 2019-11-26 06:40:03 | Cat Name 3       | TagName1        |
|       2 | Title Post 2 | 2019-11-26 06:40:03 | Cat Name 1       | TagName1        |
|       2 | Title Post 2 | 2019-11-26 06:40:03 | Cat Name 2       | TagName1        |
|       2 | Title Post 2 | 2019-11-26 06:40:03 | Cat Name 3       | TagName1        |
|       3 | Title Post 3 | 2019-11-26 06:40:03 | Cat Name 1       | TagName1        |
|       3 | Title Post 3 | 2019-11-26 06:40:03 | Cat Name 2       | TagName1        |
|       3 | Title Post 3 | 2019-11-26 06:40:03 | Cat Name 3       | TagName1        |
|       4 | Title Post 4 | 2019-11-26 06:40:03 | Cat Name 1       | TagName1        |
+---------+---------------+---------------------+------------------+-----------------+

在這里你可以看到我主頁的截圖，如果有人能幫助我達到這個，我非常感謝。

這就是我想得到的：

+---------+--------------+---------------------+------------------------------------+-----------------------------+
| id_post | title_post   | created_at          | title_categories                   | title_tags                  |
+---------+--------------+---------------------+------------------------------------+-----------------------------+
| 1       | Post title 1 | 2019-12-05 05:44:47 | Cat Name 1, Cat Name 2, Cat Name 3 | TagName1, TagName2,TagName3 |
+---------+--------------+---------------------+------------------------------------+-----------------------------+
| 2       | Post title 2 | 2019-12-05 05:44:47 | Cat Name 1, Cat Name 2             | TagName4                    |
+---------+--------------+---------------------+------------------------------------+-----------------------------+
| 3       | Post title 3 | 2019-12-05 05:44:47 | Cat Name 1                         | TagName3, TagName5,TagName6 |
+---------+--------------+---------------------+------------------------------------+-----------------------------+

提前致謝

Answer 1

這是針對您的目的的查詢，它通過加入起作用的 5 個表來工作。

select 
    p.id_post,
    p.title_post,
    p.created_at,
    group_concat(distinct c.title_category order by c.title_category) title_category,
    group_concat(distinct t.tag_title order by t.tag_title) tag_title 
from posts p
inner join post_categories pc on pc.post_id = p.id_post
inner join categories c on c.id_cat = pc.category_id
inner join post_tags pt on pt.post_id = p.id_post
inner join tags t on t.id_tag = pt.tag_id
group by
    p.id_post,
    p.title_post,
    p.created_at
order by ??
limit 10

注意：要使limit子句有意義，您需要order by條件定義order by 。 我將該子句添加到查詢中，但帶有問號，請將其替換為相關的列名。