我想知道是否有其他方法来编写此查询

Question

SELECT orderyear, numcusts
FROM (SELECT orderyear, COUNT (DISTINCT custid) AS numcustd
        FROM (SELECT YEAR ()orderdate) AS orderyear, custid
 FROM sales,Orders) AS D1
GROUP BY orderyear) AS D2

WHERE numcusts > 70;

Answer 1

试试这个：

SELECT D1.orderyear, D1.numcustd
FROM (
        SELECT YEAR(orderyear) as orderyear, COUNT (DISTINCT custid) AS numcustd
        FROM sales,Orders
        GROUP BY orderyear 
                            ) AS D1
WHERE numcusts > 70;