Why I keep getting posts.ID unknown column while the column exists? - mysql

Question

This is my WooCommerce SQL query below. I keep getting the error,
Unknown column 'posts.ID' is 'on clause'
but my posts.ID column does exist.
SELECT DISTINCT posts.ID as product_id, posts.post_parent as parent_id FROM wp_posts posts,
wp_terms terms, wp_term_relationships term_relationships LEFT JOIN wp_wc_product_meta_lookup
wc_product_meta_lookup ON posts.ID=wc_product_meta_lookup.product_id WHERE
posts.ID=term_relationships.object_id AND term_relationships.term_taxonomy_id=terms.term_id
AND terms.name!='exclude-from-catalog' AND posts.post_type IN ('product')
AND ( ( ( posts.post_title LIKE '%bruno%') OR ( posts.post_excerpt LIKE '%bruno%')
OR ( posts.post_content LIKE '%bruno%' ) OR ( wc_product_meta_lookup.sku LIKE '%bruno%' ) ))
AND posts.post_status IN ('publish') ORDER BY posts.post_parent ASC, posts.post_title ASC;

Answer 1

Never use commas in the FROM clause. Always use proper, explicit, standard JOIN syntax.
So, write the query correctly as:
SELECT DISTINCT p.ID as product_id, p.post_parent as parent_id
FROM wp_posts p JOIN
wp_term_relationships
ON p.id = tr.object_id JOIN
wp_terms t
ON tr.term_taxonomy_id = t.term_id LEFT JOIN
wp_wc_product_meta_lookup pml
ON p.ID = pml.product_id
WHERE t.name <> 'exclude-from-catalog' AND
p.post_type IN ('product') AND
(p.post_title LIKE '%bruno%' OR
p.post_excerpt LIKE '%bruno%' OR
p.post_content LIKE '%bruno%' OR
pml.sku LIKE '%bruno%'
) AND
p.post_status IN ('publish')
ORDER BY p.post_parent ASC, p.post_title ASC;
Notes:
The specific problem is that , affects the scoping of identifiers. You cannot reference a table alias from before the comma in an ON clause after the comma.
I see no reason to duplicate table names.
Using table aliases is good, but the query is simpler if the aliases are shorter.