Querying WordPress DB from normal sql - mysql

Question

Disclaimer: I am not going to use any other ways I have a specific requirement.
All I want is to Join from posts table to the posts meta so that I can get the featured image per post. I am able to get the post via where clause post type is post and published but I don't know how to write join for MySql to get the featured image of each post

Answer 1

You may try something like this:
$sql = "
SELECT $wpdb->posts.*
FROM $wpdb->posts, $wpdb->postmeta
WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id
AND $wpdb->posts.post_status = 'publish'
AND $wpdb->posts.post_type = 'post'
ORDER BY $wpdb->posts.post_date DESC
";
// Get an array of objects
$posts = $wpdb->get_results($sql, OBJECT);
You may check more here.

Answer 2

If someone else is still looking for the sql needed here you go
SET #term = "someterm"
SELECT DISTINCT
posts.id,
posts.post_author,
posts.post_title,
posts.post_date,
LEFT(posts.post_content,300) post_content,
wpmeta.meta_value thumbnail
FROM wp_posts posts
INNER JOIN wp_postmeta wpm ON posts.id = wpm.post_id
INNER JOIN wp_postmeta wpmeta ON wpm.meta_value = wpmeta.post_id
LEFT JOIN wp_term_relationships rel ON rel.object_id = posts.ID
LEFT JOIN wp_term_taxonomy tax ON tax.term_taxonomy_id = rel.term_taxonomy_id
LEFT JOIN wp_terms t ON t.term_id = tax.term_id
WHERE
post_status = 'publish'
AND posts.post_type = 'post'
AND wpm.meta_key = '_thumbnail_id'
AND wpmeta.meta_key = '_wp_attached_file'
AND 1 =
CASE
WHEN #term IS NULL THEN 1
WHEN #term IS NOT NULL AND t.term_id = #term THEN 1
ELSE 0
END
ORDER BY post_date DESC