mysql - 結合クエリにサブクエリを追加しようとしています

Question

こんな問い合わせがあります

SELECT
    tbl_products.*,
    GROUP_CONCAT(tags.name)
FROM
    tbl_page_collections_products,
    (SELECT page_collection_name as name 
       FROM tbl_page_collections 
       LEFT JOIN tbl_pages ON tbl_page_collections.page_id = tbl_pages.page_id 
       WHERE tbl_pages.page_name LIKE '%friends%') tags
    LEFT JOIN tbl_page_collections 
      ON tbl_page_collections.page_collection_id = tbl_page_collections_products.colID 
    LEFT JOIN tbl_pages 
      ON tbl_page_collections.page_id = tbl_pages.page_id 
    LEFT JOIN tbl_products 
      ON tbl_products.product_id = tbl_page_collections_products.product
   WHERE
    tbl_pages.page_name LIKE '%friends%'

私が得るエラーはUnknown column 'tbl_page_collections_products.colID in on clauseありますが、サブクエリが存在せず、その列がそのテーブルに存在する場合、そのエラーは発生しません。

何か矛盾していませんか？

Answer 1

tbl_page_collections_products は、サブクエリの from 句にはありません。多分これはあなたが望むものです：

SELECT
tbl_products.*,
GROUP_CONCAT(tags.name)
FROM
tbl_products,
(SELECT page_collection_name as name 
   FROM tbl_page_collections
   ,tbl_page_collections_products
   LEFT JOIN tbl_pages ON tbl_page_collections.page_id = tbl_pages.page_id 
   WHERE tbl_pages.page_name LIKE '%friends%') tags
LEFT JOIN tbl_page_collections 
  ON tbl_page_collections.page_collection_id = tbl_page_collections_products.colID 
LEFT JOIN tbl_pages 
  ON tbl_page_collections.page_id = tbl_pages.page_id 
LEFT JOIN tbl_products 
  ON tbl_products.product_id = tbl_page_collections_products.product
WHERE
 tbl_pages.page_name LIKE '%friends%'