SQL Inner Query WHERE clause access to Outer Query tables - mysql

Question

Good morning -
This is my first post here, after many years using SO as a very useful resource.
I've run into a problem with a complex (for me) query I'm pulling together for a wordpress site running woocommerce to process orders. I'm trying to add a filter to the order list which filters orders which contain products in a particular product category.
I'm afraid I've gotten in over my head with this query which joins a variety of meta tables on inner queries in order to get at the information I need in order to determine the product's category.
The problem is that I can't get the scoping rules to work in order to access required outer table information in the inner queries.
The query is:
SELECT SQL_CALC_FOUND_ROWS
wp_ot6q6i_posts.ID
FROM
wp_ot6q6i_posts
WHERE
1 = 1 AND YEAR(wp_ot6q6i_posts.post_date) = 2015 AND MONTH(wp_ot6q6i_posts.post_date) = 12 AND wp_ot6q6i_posts.post_type = 'shop_order' AND(
(
wp_ot6q6i_posts.post_status = 'wc-pending' OR wp_ot6q6i_posts.post_status = 'wc-processing' OR wp_ot6q6i_posts.post_status = 'wc-on-hold' OR wp_ot6q6i_posts.post_status = 'wc-completed' OR wp_ot6q6i_posts.post_status = 'wc-cancelled' OR wp_ot6q6i_posts.post_status = 'wc-refunded' OR wp_ot6q6i_posts.post_status = 'wc-failed'
)
) AND EXISTS(
SELECT
t2.PROD_ID
FROM
(
SELECT
wp_ot6q6i_woocommerce_order_itemmeta.meta_value AS PROD_ID
FROM
wp_ot6q6i_woocommerce_order_items
LEFT JOIN
wp_ot6q6i_woocommerce_order_itemmeta
ON
wp_ot6q6i_woocommerce_order_itemmeta.order_item_id = wp_ot6q6i_woocommerce_order_items.order_item_id
WHERE
wp_ot6q6i_woocommerce_order_items.order_item_type = 'line_item' AND wp_ot6q6i_woocommerce_order_itemmeta.meta_key = '_product_id' AND wp_ot6q6i_posts.ID = wp_ot6q6i_woocommerce_order_items.order_id
) t1
INNER JOIN
(
SELECT DISTINCT
wposts.ID AS PROD_ID
FROM
wp_ot6q6i_posts wposts
LEFT JOIN
wp_ot6q6i_postmeta wpostmeta
ON
wposts.ID = wpostmeta.post_id
LEFT JOIN
wp_ot6q6i_term_relationships
ON
(
wposts.ID = wp_ot6q6i_term_relationships.object_id
)
LEFT JOIN
wp_ot6q6i_term_taxonomy
ON
(
wp_ot6q6i_term_relationships.term_taxonomy_id = wp_ot6q6i_term_taxonomy.term_taxonomy_id
)
WHERE
wp_ot6q6i_term_taxonomy.taxonomy = 'product_cat' AND wp_ot6q6i_term_taxonomy.term_id IN(
SELECT
term_id
FROM
`wp_ot6q6i_terms`
WHERE
slug = 'preorder'
)
ORDER BY
wpostmeta.meta_value
) t2
ON
t1.PROD_ID = t2.PROD_ID
)
ORDER BY
wp_ot6q6i_posts.post_date
DESC
LIMIT 0, 20
And the error I'm getting is:
1054 - Unknown column 'wp_ot6q6i_posts.ID' in 'where clause'

Answer 1

Thanks all for your help. I ended up going in a different direction to solve this problem, one I'm more comfortable with as a dev...I'm pulling the fixed list of items from the last join and building a query in code that has a series of more simple queries in the where clause, thereby avoiding the whole Exists approach.
Thanks again for your help.