Wordpress custom SQL to fecth three posts with given meta values

2
votes

I have bunch of custom post type footer elements with a meta key footer_element_meta_alignment. Now, I'm trying to fetch three latest posts, which meta_values are 1, 2 and 3. So, one post with each of those values.

How can I achieve this with single SQL Query?

This is my SQL Query so far: 

"SELECT wposts.*, meta1.meta_value
FROM $wpdb->posts wposts, $wpdb->postmeta meta1
WHERE 1=1
AND wposts.post_type = 'footer_element'
AND wposts.post_status = 'publish'
AND wposts.ID = meta1.post_id
AND meta1.meta_key = 'footer_element_meta_alignment'
AND (meta1.meta_value = 1 OR meta1.meta_value = 2 OR meta1.meta_value = 3)
ORDER BY meta1.meta_value ASC";

That however fetches all elements with given meta values, and not only the latest one.

ANSWER
Answered my own question.

2
mysqlsqlwordpressgreatest-n-per-group

2 Answers

0
votes

After struggling few hours I found a solution for this.

SQL 

"SELECT *
 FROM (  SELECT p.*, m.meta_value AS meta
         FROM $wpdb->posts AS p
         LEFT JOIN $wpdb->postmeta AS m
         ON p.ID = m.post_id
         WHERE m.meta_key = 'footer_element_meta_alignment'
         AND p.post_status = 'publish'
         ORDER BY m.meta_value ASC, p.post_date DESC) AS h
 GROUP BY meta";
0
votes

Fixed (I hope).

 SELECT wposts.* FROM $wpdb->posts wposts WHERE
 wposts.post_type = 'footer_element'
 AND wposts.post_status = 'publish'
 AND wposts.ID IN 
 (SELECT max(meta1.post_id) FROM $wpdb->postmeta meta1
 WHERE meta1.meta_value = 1 OR meta1.meta_value = 2 OR meta1.meta_value = 3
 GROUP BY meta1.meta_value)