sql - 表达式不在GROUP BY键中

Question

嗨，我尝试运行此查询:

select
count(id) as Total_books_in_store,
sum(case when type in ('sports', 'music', 'history') then 1 else 0 end) AS Total_sold,
(Total_sold/Total_books_in_store) as Sales_rate
from store
group by total_in_store

当我运行此查询时，它给了我错误:
第5:1行表达式不在GROUP BY键中
我有表的ID和类型，但是我尝试计算比率没有成功。

Answer 1

;WITH Calculation AS(
    SELECT
        count(id) as Total_books_in_store,
        sum(case when type in ('sports', 'music', 'history') then 1 else 0 end) AS Total_sold
    from @Store
    group by total_in_store
)

SELECT
    Total_books_in_store,
    Total_sold,
    (Total_sold/Total_books_in_store) as Sales_rate
FROM Calculation