连接两个 sql 查询并返回一个响应

Question

如何将这两个命令总结为一个命令？

SELECT userName,userId, SUM(amount) AS total_debit FROM debts where buyerId!=userId GROUP BY userName ORDER BY userId

SELECT buyer,userId, SUM(amount) AS total_credit FROM debts where buyerId!=userId GROUP BY buyer ORDER BY userId

Answer 1

SELECT buyer,userId, SUM(amount) AS total_credit FROM debts where buyerId!=userId GROUP BY buyer,userId ORDER BY buyer,userId