MySQLクエリは変数の使用を避ける

Question

最初のクエリをメインクエリに入れ、変数のセットを避ける方法はありますか？

SET @domain_id = (SELECT id FROM stop_domain LIMIT 1); 
SELECT 
    IFNULL(MAX(duid), 0) + 1 AS duid 
    , @domain_id 
FROM 
    stop_link 
WHERE domain_id = @domain_id; 

stop_domain

id | url 

stop_link実際そこ

id | duid | domain_id 

Answer 1

あり、

SELECT 
    IFNULL(MAX(duid), 0) + 1 AS duid 
    , domain_id 
FROM 
    stop_link 
WHERE domain_id = (SELECT id FROM stop_domain LIMIT 1); 

Answer 2

これはGRなし集約クエリで示す

SELECT  IFNULL(MAX(duid), 0) + 1 AS duid 
      ,t.id 
FROM  (SELECT id FROM stop_domain LIMIT 1) t 
INNER JOIN stop_link 
ON   domain_id = t.id 
GROUP BY t.id;