Question

我正在尝试动态使用where子句的日期范围内的日期作为结果中的列名称。我知道我可以使用case / when语句对其进行硬编码：

sum(case when day(date_accessed) = 1 THEN 1 ELSE 0 END) AS `Jan 1 2014`...

每个月这样做会很麻烦。我也知道我可以使用php或其他一些脚本语言来构建表，但我正在尝试在mysql中完成所有这些。这是我的查询。

SELECT count(*) AS `Total Clicks`, day(date_accessed)
FROM Client_Activity_Log a WHERE date_accessed between '2014-01-01' AND '2014-01-31'
GROUP BY day(date_accessed);

上面的查询会将每个日期放入自己的行并将其合计，但我希望每个日期都是列。我希望结果看起来像这样（一月中的所有日子）：

Jan 1 2014      Jan 2 2014
150             200

Answer 1

我可能找到了一个不错的解决方案。让我知道是否有人有更好的：

我可能已经找到了最简单的解决方案。它不会在列名中提供月份或年份，但可能会尽可能接近：

SELECT 
SUM(CASE WHEN day(date_accessed) = 1 THEN 1 ELSE 0 END) AS '1', 
SUM(CASE WHEN day(date_accessed) = 2 THEN 1 ELSE 0 END) AS `2`, 
SUM(CASE WHEN day(date_accessed) = 3 THEN 1 ELSE 0 END) AS `3`, 
SUM(CASE WHEN day(date_accessed) = 4 THEN 1 ELSE 0 END) AS `4`, 
SUM(CASE WHEN day(date_accessed) = 5 THEN 1 ELSE 0 END) AS `5`, 
SUM(CASE WHEN day(date_accessed) = 6 THEN 1 ELSE 0 END) AS `6`, 
SUM(CASE WHEN day(date_accessed) = 7 THEN 1 ELSE 0 END) AS `7`, 
SUM(CASE WHEN day(date_accessed) = 8 THEN 1 ELSE 0 END) AS `8`, 
SUM(CASE WHEN day(date_accessed) = 9 THEN 1 ELSE 0 END) AS `9`, 
SUM(CASE WHEN day(date_accessed) = 10 THEN 1 ELSE 0 END) AS `10`, 
SUM(CASE WHEN day(date_accessed) = 11 THEN 1 ELSE 0 END) AS `11`, 
SUM(CASE WHEN day(date_accessed) = 12 THEN 1 ELSE 0 END) AS `12`, 
SUM(CASE WHEN day(date_accessed) = 13 THEN 1 ELSE 0 END) AS `13`, 
SUM(CASE WHEN day(date_accessed) = 14 THEN 1 ELSE 0 END) AS `14`, 
SUM(CASE WHEN day(date_accessed) = 15 THEN 1 ELSE 0 END) AS `15`, 
SUM(CASE WHEN day(date_accessed) = 16 THEN 1 ELSE 0 END) AS `16`, 
SUM(CASE WHEN day(date_accessed) = 17 THEN 1 ELSE 0 END) AS `17`, 
SUM(CASE WHEN day(date_accessed) = 18 THEN 1 ELSE 0 END) AS `18`, 
SUM(CASE WHEN day(date_accessed) = 19 THEN 1 ELSE 0 END) AS `19`, 
SUM(CASE WHEN day(date_accessed) = 20 THEN 1 ELSE 0 END) AS `20`, 
SUM(CASE WHEN day(date_accessed) = 21 THEN 1 ELSE 0 END) AS `21`, 
SUM(CASE WHEN day(date_accessed) = 22 THEN 1 ELSE 0 END) AS `22`, 
SUM(CASE WHEN day(date_accessed) = 23 THEN 1 ELSE 0 END) AS `23`, 
SUM(CASE WHEN day(date_accessed) = 24 THEN 1 ELSE 0 END) AS `24`, 
SUM(CASE WHEN day(date_accessed) = 25 THEN 1 ELSE 0 END) AS `25`, 
SUM(CASE WHEN day(date_accessed) = 26 THEN 1 ELSE 0 END) AS `26`, 
SUM(CASE WHEN day(date_accessed) = 27 THEN 1 ELSE 0 END) AS `27`,
SUM(CASE WHEN day(date_accessed) = 28 THEN 1 ELSE 0 END) AS `28`,
SUM(CASE WHEN day(date_accessed) = 29 THEN 1 ELSE 0 END) AS `29`,
SUM(CASE WHEN day(date_accessed) = 30 THEN 1 ELSE 0 END) AS `30`,
SUM(CASE WHEN day(date_accessed) = 31 THEN 1 ELSE 0 END) AS `31`
FROM Client_Activity_Log a WHERE date_accessed between '2014-01-01' AND '2014-01-31';

在where子句中使用日期范围作为列名

1 个答案: