How to Write a SQL Query to Display list of most used tags in the last 30 days in Wordpress website - sql

Question

I am looking for a way to display the most used tags over the last 30 days on my Baseball blog, built on Wordpress. I am no coder, but I have come up with this mashup to display a list of the most used 28 tags (preference to fit my theme). I cannot, for the life of me, figure out how to limit the tags to the most used in the last 30 days.
Here is what I have:
<ul id="footer-tags">
<?php
global $wpdb;
$term_ids = $wpdb->get_col("
SELECT DISTINCT term_taxonomy_id FROM $wpdb->term_relationships
INNER JOIN $wpdb->posts ON $wpdb->posts.ID = object_id
WHERE DATE_SUB(CURDATE(), INTERVAL 30 DAY) <= $wpdb->posts.post_date");
if(count($term_ids) > 0){
$tags = get_tags(array(
'orderby' => 'count',
'order' => 'DESC',
'number' => 28,
'include' => $term_ids,
));
foreach ( (array) $tags as $tag ) {
echo '<li>' . $tag->name . '</li>';
}
}
?>
</ul>
The website is slightly less than ~4 weeks old, so to test, I changed INTERVAL 30 DAY to INTERVAL 3 DAY and the tags being returned seem random and some haven't been used in 2+ weeks and have only been used a single time. As well, only 8 tags are being displayed, when more have been used.
To check that the correct number of days have been queried, I did the following:
Completely deleted all items in the trash for posts and pages, I don't have any custom post types.
Did the same with drafts.
Ran a query in phpmyadmin to delete all post revisions - DELETE FROM wp_posts WHERE post_type = "revision";
Ran a query in phpmyadmin to check if the results are the posts from the last 3 days - SELECT * from wp_posts WHERE DATE_SUB(CURDATE(), INTERVAL 3 DAY) <= post_date
The results from the phpmyadmin query were, in fact, the posts from the last 3 days, but the front-end display did not change.
UPDATE
Here are some screen shots. Maybe the screenshots can help find where my code is wrong.
Blog Post with Category and Tags
wp_posts table with the post ID of above post
wp_terms table with the term_id of the tags used
wp_term_taxonomy with the tags' term_id as term_taxonomy_id
wp_term_relationships with term_taxonomy_id assigned to post as object_id
UPDATE 2
I think I figured out the problem, but do not know how to fix it.
The SQL query gets the term_taxonomy_id, not the actual tag ID and get_tag_link uses term_id
UPDATE 3
I have recently created a plugin to display the most popular recently used tags - https://wordpress.org/plugins/recent-popular-tags/

Answer 1

The PHP variables you are inserting in your SQL string are the PHP objects that can be used to access WordPress tables from within PHP; whereas you are after the names of the tables and columns for accessing the data from within SQL.
You want instead:
"SELECT DISTINCT term_taxonomy_id FROM wp_term_relationships
INNER JOIN wp_posts ON wp_posts.ID = wp_term_relationships.object_id
WHERE DATE_SUB(CURDATE(), INTERVAL 30 DAY) <= wp_posts.post_date"
As an aside: should you ever need to insert the value of a PHP variable into a SQL statement, be very careful to escape it first in order to prevent any malicious code from being injected.

Answer 2

The problem was that the SQL query code was getting the term_taxonomy_id, not the actual tag ID.
I added an additional INNER JOIN using the term_taxonomy table to get the term_id. This seems to work, but if a mod can improve this, please do!
<ul id="footer-tags">
<?php $wpdb->show_errors(); ?>
<?php
global $wpdb;
$term_ids = $wpdb->get_col("
SELECT term_id FROM $wpdb->term_taxonomy
INNER JOIN $wpdb->term_relationships ON $wpdb->term_taxonomy.term_taxonomy_id=$wpdb->term_relationships.term_taxonomy_id
INNER JOIN $wpdb->posts ON $wpdb->posts.ID = $wpdb->term_relationships.object_id
WHERE DATE_SUB(CURDATE(), INTERVAL 30 DAY) <= $wpdb->posts.post_date");
if(count($term_ids) > 0){
$tags = get_tags(array(
'orderby' => 'count',
'order' => 'DESC',
'number' => 28,
'include' => $term_ids,
));
foreach ( (array) $tags as $tag ) {
echo '<li>' . $tag->name . '</li>';
}
}
?>
</ul>
UPDATE
I have recently created a plugin to display the most popular recently used tags - https://wordpress.org/plugins/recent-popular-tags/