选择所有帖子及其类别和标签以显示在主页上

Question

I want to Select all posts and their categories and tags to display in main page, also I want to select all categories and tags for a single post in other query to display on post-page, at this moment I have done, but I'm using 3 querys inside a foreach to get all data, but I think it was redundat and I wish to Know if it is possible to take all data in a single query, this is an reduced example of my tables:

POSTS

| 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 |
+---------+-------------+

CATEGORIES

+--------+----------------+
| 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 |
+---------+-----------+

TAGS

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

So to display in main page I use this:

$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 send the info to BlogModel and excecute this querys for categories and tags:

$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";

So I would like to do a single query to get all info I try to do this:

$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";

And here are the results(RESULTS LIMITED TO 10 just for don't print a big data):

+---------+---------------+---------------------+------------------+-----------------+
| 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        |
+---------+---------------+---------------------+------------------+-----------------+

Here you can see an screenshot from my main page, If anyone can help me to reach this I appreciate it so much thanks.

This is what I would like to get:

+---------+--------------+---------------------+------------------------------------+-----------------------------+
| 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 |
+---------+--------------+---------------------+------------------------------------+-----------------------------+

Thanks in advance

Answer 1

Here is query for your purpose, which works by joining the 5 tables that come into play.

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

Note: for the limit clause to make sense, you would need to define order by criterias. I added that clause to the query but with question marks, please replace that with the relevant column names.