一种可能的解决方案是创建一个视图，这样每次执行查询时就不需要将大量数据加载到结果中。而且更容易维护，因为您可以在视图中过滤或删除不再需要的列。
例子：

CREATE VIEW clienti_con_rinnovo
AS
SELECT
    id,
    MAX(dateTransaction) AS last_transaction_renew
    FROM transactions
    WHERE
    renew IS NOT NULL
    GROUP BY id

但你的尝试几乎成功了。尝试：

SELECT clienti_con_rinnovo.* FROM
( SELECT
    id,
    MAX(dateTransaction) AS last_transaction_renew
    FROM transactions
    WHERE
    renew IS NOT NULL
    GROUP BY id ) AS clienti_con_rinnovo

另一张table也是这样：

SELECT clienti_senza_rinnovo.* FROM
    ( SELECT
            id,
            MAX(dateTransaction) AS last_transaction_renew
      FROM transactions
      WHERE renew IS NULL
      GROUP BY id ) AS clienti_senza_rinnovo

我不知道你想做什么，但别名不工作的方式，你试图实现它在这里。试着用这个

SELECT * FROM
 ( SELECT
 id,
 MAX(dateTransaction) AS last_transaction_renew
 FROM transactions
 WHERE
 renew IS NOT NULL
 GROUP BY id ) AS clienti_con_rinnovo_new

 UNION

 SELECT clienti_senza_rinnovo.* FROM 
 ( SELECT
   id,
   MAX(dateTransaction) AS last_transaction_renew
     FROM transactions
    WHERE
    renew IS NOT NULL
  GROUP BY id ) AS clienti_con_rinnov
LEFT JOIN 
(SELECT
   id,
  MAX(dateTransaction) AS last_transaction_renew
  FROM transactions
  WHERE renew IS NULL
  GROUP BY id ) AS clienti_senza_rinnovo ON clienti_con_rinnovo.id = 
  clienti_senza_rinnovo.id 
  WHERE clienti_con_rinnovo.id IS NULL