Question

我在表中有以下数据，并且需要获取数据透视表输出。我无法为自己的生命解决这个问题。预先感谢.....

mysql表中的行

id, timestamp, metric, value
1, 2020-10-31 02:52:02.144030, aaaa, 3
2, 2020-10-31 02:52:02.144030, tttt, 40
3, 2020-10-31 02:52:02.144030, vvvv, 6
4, 2020-10-31 02:53:01.656349, aaaa, 3
5, 2020-10-31 02:53:01.656349, tttt, 40
6, 2020-10-31 02:53:01.656349, vvvv, 6
7, 2020-10-31 02:54:02.053597, aaaa, 3
8, 2020-10-31 02:54:02.053597, tttt, 40
9, 2020-10-31 02:54:02.053597, vvvv, 6
10, 2020-10-31 02:55:01.490467, aaaa, 3
11, 2020-10-31 02:55:01.490467, tttt, 40
12, 2020-10-31 02:55:01.490467, vvvv, 6

我正在寻找的输出

timestamp, aaaa, tttt, vvvv
2020-10-31 02:52:02.144030, 3, 40, 6
2020-10-31 02:53:01.656349, 3, 40, 6
2020-10-31 02:54:02.053597, 3, 40, 6
2020-10-31 02:55:01.490467, 3, 40, 6

Answer 1

您可以通过使用GROUP_CONCAT()和CONCAT()函数（例如

SET @sql = NULL;

SELECT GROUP_CONCAT(                 
             CONCAT(
                    'MAX(CASE WHEN metric = "', metric,'" THEN value END ) AS ',metric
                    )
       )
  INTO @sql
  FROM ( SELECT DISTINCT metric FROM tab) t;

SET @sql = CONCAT('SELECT timestamp,',@sql,' FROM tab GROUP BY timestamp'); 

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

Demo

mysql时间序列数据到数据透视表

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