MySQL到PHP数组分组重复值

Question

请对我温柔一点，因为我正在学习使用手册、反复试验和（咳咳）开源软件的逆向工程。

我有一个 MySQL 查询，它返回如下表（该查询已经相当复杂，因为它包括来自连接表的总和和计数）：

   DATE      ANSWER   CATEGORY    COUNT
2011-01-01      Y       CAT1       22
2011-01-01      Y       CAT2       220
2011-01-01      N       CAT1       14
2011-01-01      N       CAT2       530
2011-01-02      Y       CAT1       50
2011-01-02      Y       CAT2       270
2011-01-02      N       CAT1       18
2011-01-02      N       CAT2       576

我需要将所有内容放在带有日期的单行中，例如

   DATE      Total Y     Total N     Total Cat1    Total Cat2    Total Overall
2011-01-01     242         544           36            750            786
2011-01-02     320         594           68            750            846

现在我假设要获得这些数字，我需要将它们分组到一个多维数组中，以便我可以像这样玩这些数字：

Array
(
 2011-01-01 => Array (
    Y => Array(
        [CAT1] = 22
        [CAT2] = 220
        )
    N => Array(
        [CAT1] = 14
        [CAT2] = 530
        )
     )
 2011-01-02 => Array (
    Y => Array(
        [CAT1] = 50
        [CAT2] = 270
        )
    N => Array(
        [CAT1] = 18
        [CAT2] = 576
        )
     )
)

但这就是我卡住的地方我似乎无法弄清楚在这种情况下将数据放入数组中的 foreach 循环，一旦它在那里，我如何在表格中显示它？

任何帮助将不胜感激。

Answer 1

SELECT
  DATE,
  SUM(CASE ANSWER WHEN 'Y' THEN COUNT ELSE 0 END) AS TotalY,
  SUM(CASE ANSWER WHEN 'N' THEN COUNT ELSE 0 END) AS TotalN,
  SUM(CASE CATEGORY WHEN 'CAT1' THEN COUNT ELSE 0 END) AS TotalCat1,
  SUM(CASE CATEGORY WHEN 'CAT2' THEN COUNT ELSE 0 END) AS TotalCat2,
  SUM(COUNT) AS TotalOverall
FROM subquery
GROUP BY DATE

Answer 2

您可以从查询本身获得结果。

我知道这不是最好的查询，但它可以让您了解如何解决您想要的问题

SELECT theDate AS `DATE`, 
    (SELECT SUM(theCount) FROM st WHERE theAnswer = 'Y' AND theDate = a.theDate) AS 'Total Y',
    (SELECT SUM(theCount) FROM st WHERE theAnswer = 'N' AND theDate = a.theDate) AS 'Total N',
    (SELECT SUM(theCount) FROM st WHERE theCategory = 'CAT1' AND theDate = a.theDate) AS 'Total Cat1',
    (SELECT SUM(theCount) FROM st WHERE theCategory = 'CAT2' AND theDate = a.theDate) AS 'Total Cat2',
    (SELECT SUM(theCount) FROM st WHERE theCategory IN('CAT1','CAT2') AND theDate = a.theDate) AS 'Total Overall'
FROM st AS a
GROUP BY theDate

结果：

   DATE      Total Y     Total N     Total Cat1    Total Cat2    Total Overall
2011-01-01     242         544           36            750            786
2011-01-02     320         594           68            846            914

Answer 3

您可以直接从 SQL 数据库中提取所需的数据。

试试：

SELECT `DATE`, ANSWER, SUM(`COUNT`) as TOTAL 
FROM table -- Change this!
GROUP BY `DATE`, ANSWER

并将 ANSWER 替换为 CATEGORY 以获得按类别的总数。