SQL 获取一些大于值的值，但没有工作

Question

我有这个代码：

Select firstname, lastname, sum(quantity) as quantitySum
FROM Customer
JOIN "Order"
ON Customer.id = "Order".customerid
JOIN orderitem
ON "Order".id = orderitem.orderid
WHERE country = 'Germany'
GROUP BY firstname, lastname
HAVING quantitySum > 500
ORDER BY lastname

但这给了我一个错误。 我想不明白。 每次帮助都很高兴！

Answer 1

Having group by然后select之后执行子句，因此您必须使用聚合的 function 并having以下内容

Select firstname, lastname, sum(quantity) as quantitySum
FROM Customer
JOIN "Order"
ON Customer.id = "Order".customerid
JOIN orderitem
ON "Order".id = orderitem.orderid
WHERE country = 'Germany'
GROUP BY firstname, lastname
HAVING sum(quantity) > 500
ORDER BY lastname