的SQL請求，dublicates所有內容

Question

我寫的與作者一起檢索的Joomla文章SQL請求：

static function getLists(&$params) 
    { 
     $db  = JFactory::getDbo(); 
     $lists = null; 
     $query = "SELECT cc.title AS category, a.id, a.title, a.created as created, av.add_image as imgthrumb, ua.avatar as avatar, ar.intotext as introtext, ss.userid as onlineid, 
     u.id AS userlink, u.username as username, u.lastvisitDate as lastvisit, a.hits, cc.id as catid, a.state as state, a.created_by as authorid, mp.group_id as groupid, ug.title as ugtitle 
     FROM #__content AS a 
     LEFT JOIN #__categories AS cc ON a.catid = cc.id 
     LEFT JOIN #__users AS u ON u.id = a.created_by 
     LEFT JOIN #__cck_store_item_content AS av ON av.id = a.id 
     LEFT JOIN #__comprofiler AS ua ON user_id = a.created_by 
     LEFT JOIN #__cck_store_item_cck_store_item_content AS ar ON ar.id = a.id 
     LEFT JOIN #__user_usergroup_map AS mp ON mp.user_id = a.created_by 
     LEFT JOIN #__usergroups AS ug ON ug.id = mp.group_id 
     LEFT JOIN #__session AS ss ON ss.userid = u.id AND ss.userid > 0 AND ss.guest = 0 
     WHERE a.created_by = u.id AND a.id >0 
     AND DATE(a.created) >= DATE_SUB(CURRENT_DATE, INTERVAL ".(int)$safe_date." DAY) AND a.access = 1 AND a.state = 1 AND a.created > 0 
     ORDER BY created desc"; 
     $db->setQuery($query,0,10); 
     $lists = $db->loadObjectList();   

     return $lists; 

    } 

它的工作原理就像一個魅力，但繼承人一些奇怪的一部分，如果我登錄不同的瀏覽器相同的用戶，它會將所有內容複製兩次，如果我第三次登錄，它將複製所有內容3次，等等！據我所見，問題出在這一行：

LEFT JOIN #__session AS ss ON ss.userid = u.id AND ss.userid > 0 AND ss.guest = 0 

有什麼建議嗎？

Answer 1

它重複，因爲從另一個瀏覽器登錄爲該用戶創建一個新的會話。嘗試做

SELECT DISTINCT 
... 

Answer 2

您可能想要爲此user_id添加一個別名，以便數據庫知道此user_id引用了哪個表。

LEFT JOIN #__comprofiler AS ua ON user_id = a.created_by

我會跑小版本的查詢，看看當開始越來越推出的副本。從前3個表格連接開始。如果您沒有看到重複項，請再添加一個連接，以便您加入查詢中的前四個表。將有助於準確找到引入問題的位置。