Question

我正在尝试编写一个SQLite查询，该查询获取值的总出现次数除以月份。

所需输出的示例：

Name   Jun  Jul  Aug  Sept
John   3    2    5    2
Robert 4    12   45   22
Linda  0    2    1    0

我希望Name字段仅返回唯一结果，因此每次“John”出现在Jun，Jul等月时它基本上都会计算。

这是我到目前为止使用我的实际数据库。它可以返回正确的列和唯一的“ReasonDetail”，但计数不准确：

SELECT * FROM

(
    SELECT ReasonDetail AS Appetite, COUNT(*) AS June
        FROM CallRecords
        WHERE CallReason = 'Appetite Question'
        AND DateTime BETWEEN  '2017-06-01 00:00' AND '2017-07-01 00:00'
        GROUP BY ReasonDetail
),
(
    SELECT COUNT(*) AS July
        FROM CallRecords
        WHERE CallReason = 'Appetite Question'
        AND DateTime BETWEEN  '2017-07-01 00:00' AND '2017-08-01 00:00'
        GROUP BY ReasonDetail
),
(
    SELECT COUNT(*) AS August
        FROM CallRecords
        WHERE CallReason = 'Appetite Question'
        AND DateTime BETWEEN  '2017-08-01 00:00' AND '2017-09-01 00:00'
        GROUP BY ReasonDetail
)
GROUP BY Appetite

我在这里做错了什么？在这种情况下，有没有更好的方法来编译正确的计数？

谢谢！

Answer 1

这称为条件聚合。在聚合函数中使用open(FILE, ">" ,$file ) FILE->autoflush; $self->{FILEH} = *FILE;表达式。

case

SQLite将多个查询与共享列组合在一起

1 个答案: