Question

如果我有查询

SELECT id,name,SUM(investments) as total_investments, SUM(investments)/10 as per_ten_investment
FROM table1
GROUP BY name

我有什么方法可以在计算per_ten_investment时使用total_investments？因此，我可以使用

而不是上述内容

SELECT id,name,SUM(investments) as total_investments, total_investments/10 as per_ten_investment
FROM table1
GROUP BY name

以上导致错误未知栏＆＃39; total_investments＆＃39;在＆＃39;字段列表＆＃39;

我遇到的问题要复杂得多，但归结为这个障碍。谢谢大家。

Answer 1

一个选项是使用子查询，然后您可以引用求和字段。话虽如此，我认为您的查询没有任何问题：

SELECT id, name, total_investments, total_investments/10 per_ten_investment
FROM (SELECT id, name, SUM(investments) as total_investments
    FROM table1
    GROUP BY name) t

此外，根据您的数据，您可能希望将id字段添加到group by。 Mysql对其他人更宽容。

Answer 2

这也应该有用

SELECT id,name,SUM(investments) as total_investments, SUM(investments)/10 as per_ten_investment
FROM table1
GROUP BY name

在另一列中重用列的结果

2 个答案: