我只需要使用条件聚合。在mysql中枚举值有点棘手（除非您使用的是mysql 8+）：

select datetime,
       max(case when rn = 1 then title end) as title_1,
       max(case when rn = 1 then feedback end) as feedback_1,
       max(case when rn = 2 then title end) as title_2,
       max(case when rn = 2 then feedback end) as feedback_2,
       max(case when rn = 3 then title end) as title_3,
       max(case when rn = 3 then feedback end) as feedback_3,
       max(case when rn = 4 then title end) as title_4,
       max(case when rn = 4 then feedback end) as feedback_4,
       max(case when rn = 5 then title end) as title_5,
       max(case when rn = 5 then feedback end) as feedback_5,
       max(case when rn = 6 then title end) as title_6,
       max(case when rn = 6 then feedback end) as feedback_6
from (select gc.*,
             (@rn := if(@dt = g.dateTime, @rn + 1,
                        if(@dt := g.dateTime, 1, 1)
                       )
             ) as rn
      from (select g.dateTime, g.feedback, c.title AS title    
            from gauge g inner join
                 category c
                 on g.category_id = c.category_id and
                    c.title = 'title' and
                    g.feedback = 'feedback' 
            group by g.dateTime
            order by g.dateTime
           ) gc cross join
           (select @dt := '', @rn := 0) params
     ) gc
group by datetime;

我不认为过滤 c.title 以及 g.feedback 是正确的。

不是一种优化的方法，但您可以将它们连接到表中，并根据行数模6进行过滤。这样，我们可以将这6行分为6个不同的表
http://rextester.com/dlvv64095

SELECT MAIN.DateTime,
    TBL1.TITLE AS Title1,
    TBL1.FEEDBACK AS Feedback1,
    TBL2.TITLE AS Title2,
    TBL2.FEEDBACK AS Feedback2,
    TBL3.TITLE AS Title3,
    TBL3.FEEDBACK AS Feedback3,
    TBL4.TITLE AS Title4,
    TBL4.FEEDBACK AS Feedback4,
    TBL5.TITLE AS Title5,
    TBL5.FEEDBACK AS Feedback5,
    TBL6.TITLE AS Title6,
    TBL6.FEEDBACK AS Feedback6
FROM (
    SELECT [DATETIME] AS [DateTime]
    FROM GAUGE
    GROUP BY [DATETIME]
) MAIN
INNER JOIN (
    SELECT G.DATETIME,
        G.FEEDBACK,
        C.TITLE,
        ROW_NUMBER() OVER(PARTITION BY ORDER BY (SELECT 1) ASC) AS ROWNO
    FROM GAUGE G
    INNER JOIN CATEGORY C
        ON G.CATEGORY_ID = C.CATEGORY_ID
) TBL1
    ON TBL1.DATETIME = MAIN.[DateTime]
    AND TBL1.ROWNO % 6 = 1
INNER JOIN (
    SELECT G.DATETIME,
        G.FEEDBACK,
        C.TITLE,
        ROW_NUMBER() OVER(PARTITION BY ORDER BY (SELECT 1) ASC) AS ROWNO
    FROM GAUGE G
    INNER JOIN CATEGORY C
        ON G.CATEGORY_ID = C.CATEGORY_ID
) TBL2
    ON TBL2.DATETIME = MAIN.[DateTime]
    AND TBL2.ROWNO % 6 = 2
INNER JOIN (
    SELECT G.DATETIME,
        G.FEEDBACK,
        C.TITLE,
        ROW_NUMBER() OVER(PARTITION BY ORDER BY (SELECT 1) ASC) AS ROWNO
    FROM GAUGE G
    INNER JOIN CATEGORY C
        ON G.CATEGORY_ID = C.CATEGORY_ID
) TBL3
    ON TBL3.DATETIME = MAIN.[DateTime]
    AND TBL3.ROWNO % 6 = 3
INNER JOIN (
    SELECT G.DATETIME,
        G.FEEDBACK,
        C.TITLE,
        ROW_NUMBER() OVER(PARTITION BY ORDER BY (SELECT 1) ASC) AS ROWNO
    FROM GAUGE G
    INNER JOIN CATEGORY C
        ON G.CATEGORY_ID = C.CATEGORY_ID
) TBL4
    ON TBL4.DATETIME = MAIN.[DateTime]
    AND TBL4.ROWNO % 6 = 4
INNER JOIN (
    SELECT G.DATETIME,
        G.FEEDBACK,
        C.TITLE,
        ROW_NUMBER() OVER(PARTITION BY ORDER BY (SELECT 1) ASC) AS ROWNO
    FROM GAUGE G
    INNER JOIN CATEGORY C
        ON G.CATEGORY_ID = C.CATEGORY_ID
) TBL5
    ON TBL5.DATETIME = MAIN.[DateTime]
    AND TBL5.ROWNO % 6 = 5
INNER JOIN (
    SELECT G.DATETIME,
        G.FEEDBACK,
        C.TITLE,
        ROW_NUMBER() OVER(PARTITION BY ORDER BY (SELECT 1) ASC) AS ROWNO
    FROM GAUGE G
    INNER JOIN CATEGORY C
        ON G.CATEGORY_ID = C.CATEGORY_ID
) TBL6
    ON TBL6.DATETIME = MAIN.[DateTime]
    AND TBL6.ROWNO % 6 = 0

使用动态轴，因为有许多不同的值
摆弄

drop table t;
create table t
(
  dateTime datetime,
  title varchar(50),
  feedback int
);

insert into t values
( '2018-06-29 12:55:36', 'A', 1),
( '2018-06-29 12:55:36', 'B', 2),
( '2018-06-22 12:55:36', 'A', 1),
( '2018-06-22 12:55:36', 'B', 2),
( '2018-06-22 12:55:36', 'C', 3);

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'MAX(CASE WHEN title = ''',
      title,
      ''' THEN ''', title ,''' END) AS ',
      CONCAT(' Title',title,',')
    ),
     CONCAT(
      'MAX(CASE WHEN feedback = ''',
      feedback,
      ''' THEN ''', feedback ,''' END) AS ',
      CONCAT(' Feedback',feedback)
    )
  ) INTO @sql
FROM T;

SET @sql = CONCAT('SELECT dateTime, ', @sql, ' 
                   FROM t
                   GROUP BY dateTime');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;