Sql - merge 2 queries into 1

SELECT 
all_combos.user_id, 
all_combos.item_id, 
COALESCE(T.stat, 0) AS stat, 
COALESCE(T.dup) AS dup, 
t2.item_group
FROM 
>   (
SELECT 
user_id, 
item_id 
FROM 
>       (SELECT DISTINCT user_id FROM table3) u, 
>       (SELECT DISTINCT item_id FROM table3) i
AS all_combos 
LEFT OUTER JOIN table3 T ON T.user_id = all_combos.user_id AND T.item_id = all_combos.item_id
LEFT OUTER JOIN table2 t2 ON t2.id = all_combos.item_id
WHERE t2.item_group= 'LAMPS';

SELECT t8.username AS 'Username', 
            GROUP_CONCAT(CASE WHEN t3.dup=1 AND t4.stat=0 AND t2.item_group='LAMPS' THEN item_no END ORDER BY item_id SEPARATOR ', ') `My Items List`,
            GROUP_CONCAT(CASE WHEN t4.dup=1 AND t3.stat=0 AND t2.item_group='LAMPS' THEN item_no END ORDER BY item_id SEPARATOR ', ') `Item List`,
            SUM(CASE WHEN t4.dup=1 AND t3.stat=0 AND t2.item_group='LAMPS' THEN 1 ELSE 0 END) as `All_dup_sum`
            FROM table3 t3
            LEFT JOIN table3 t4 USING (item_id)
            JOIN table2 t2 ON t2.id = t4.item_id
            JOIN accounts t8 ON t8.id = t4.user_id
            WHERE t3.user_id = 23
              AND t4.user_id <> 23
              GROUP BY t4.user_id
              HAVING `Item List` is not null or `My Items List` is not null
              ORDER BY SUM(CASE WHEN t4.dup=1 AND t3.stat=0 AND t2.item_group='LAMPS' THEN 1 ELSE 0 END) DESC,
                       SUM(CASE WHEN t3.dup=1 AND t4.stat=0 AND t2.item_group='LAMPS' THEN 1 ELSE 0 END);

SQL - Merge 2 queries into 1