您可以使用查询并执行FULL OUTER JOIN来连接它们，当两者都是可选的时：

SELECT COALESCE(p.personId, ep.personId) AS personId,
       p.personAmountPayments,
       ep.personAmountExtraPayments
FROM   (
         select personId,
                sum(amount) as personAmountPayments
         from   payments
         where  code         = '023'
         and    paiementDate = DATE '2023-04-01'
         group by personId
       ) p
       FULL OUTER JOIN
       (
         select personId,
                sum(amount) as personAmountExtraPayments
         from   extraPayments
         where  code         = '23'
         and    paiementDate = DATE '2023-04-01'
         group by personId
       ) ep
       ON p.personId = ep.personId;