mySQL GROUP_CONCAT加入

Question

I have the following SQL. I am trying to perform a GROUP_CONCAT within a Join but no matter how I seem try it doesnt seem to work right.

Essentially there is a link tag table that does a one to many on another table that holds tags. So there might be say 8 tags for one article record. I need them concatenated together .vs. ending up with 8 records.

SELECT 
  `articles`.`art_title`,
  `articles`.`art_bodytext`,
  `info`.`inf_start_date`,
  `info`.`inf_end_date`,
  `info`.`inf_hits`,
  `info`.`inf_acl`,
  `category`.`name`,
  `options`.`opt_tpl`,
  `options`.`opt_published`,
  `options`.`opt_options`,
  `options`.`opt_acl`,
  `tags`.`tag`
FROM
  `linktable`
  INNER JOIN `articles` ON (`linktable`.`lnk_data_id` = `articles`.`art_id`)
  INNER JOIN `info` ON (`articles`.`art_info_id` = `info`.`inf_id`)
  INNER JOIN `category` ON (`articles`.`art_cat_id` = `category`.`id`)
  AND (`articles`.`art_cat_tree_id` = `category`.`fid`)
  INNER JOIN `options` ON (`articles`.`art_opt_id` = `options`.`opt_id`)
  INNER JOIN `linktags` ON (`articles`.`art_tag_set_id` = `linktags`.`lnk_tagset_id`)
  LEFT OUTER JOIN GROUP_CONCAT(`tags`) ON (`linktags`.`lnk_tag_id` = `tags`.`tag_id`)
WHERE
  `linktable`.`lnk_pgc_id` = 1

Answer 1

• Move the GROUP_CONCAT() into the field list, it is not a join condition, but a field calculation.
• Add a GROUP BY to find the rows to combine

This gives

SELECT 
  `articles`.`art_title`,
  `articles`.`art_bodytext`,
  `info`.`inf_start_date`,
  `info`.`inf_end_date`,
  `info`.`inf_hits`,
  `info`.`inf_acl`,
  `category`.`name`,
  `options`.`opt_tpl`,
  `options`.`opt_published`,
  `options`.`opt_options`,
  `options`.`opt_acl`,
  GROUP_CONCAT(`tags`.`tag`) AS tags
FROM
  `linktable`
  INNER JOIN `articles` ON (`linktable`.`lnk_data_id` = `articles`.`art_id`)
  INNER JOIN `info` ON (`articles`.`art_info_id` = `info`.`inf_id`)
  INNER JOIN `category` ON (`articles`.`art_cat_id` = `category`.`id`)
  AND (`articles`.`art_cat_tree_id` = `category`.`fid`)
  INNER JOIN `options` ON (`articles`.`art_opt_id` = `options`.`opt_id`)
  INNER JOIN `linktags` ON (`articles`.`art_tag_set_id` = `linktags`.`lnk_tagset_id`)
  LEFT JOIN `tags` ON (`linktags`.`lnk_tag_id` = `tags`.`tag_id`)
WHERE
  `linktable`.`lnk_pgc_id` = 1
GROUP BY `articles`.`art_id`