Question

无法理解此SQL有什么问题。

我认为它以前可以在MySQL上运行。无论如何，它现在不适用于MariaDB。

表如下：

MariaDB [piHeatingDB]> SELECT * FROM powerLog LIMIT 4;
+----+---------------------+-----------+-----------+-----------+------------------+------------------+------------------+--------+-------+
| id | ts                  | currentR1 | currentS2 | currentT3 | currentAverageR1 | currentAverageS2 | currentAverageT3 | pulses | event |
+----+---------------------+-----------+-----------+-----------+------------------+------------------+------------------+--------+-------+
|  1 | 2020-03-15 16:28:10 |      0.97 |      0.08 |      0.94 |             0.87 |             0.08 |             0.84 |      0 | cron  |
|  2 | 2020-03-15 16:30:09 |      0.93 |      0.07 |      0.91 |             0.87 |             0.08 |             0.84 |      0 | cron  |
|  3 | 2020-03-15 16:32:38 |         0 |         0 |         0 |                0 |                0 |                0 |      0 | cron  |
|  4 | 2020-03-15 16:34:22 |         0 |         0 |         0 |                0 |                0 |                0 |      0 | cron  |
+----+---------------------+-----------+-----------+-----------+------------------+------------------+------------------+--------+-------+
4 rows in set (0.009 sec)

这是错误的SQL：

SELECT 
  currentAverageR1, 
  currentAverageS2, 
  currentAverageT3, 
FROM 
  powerLog 
WHERE 
  ts > DATE_SUB(
    '2020-03-15 18:30:03', INTERVAL 1 MINUTE
  ) 
  AND ts < DATE_ADD(
    '2020-03-15 18:30:03', INTERVAL 1 MINUTE
  ) 
LIMIT 
  1

这给了我

MariaDB [piHeatingDB]> SELECT 
->   currentAverageR1, 
->   currentAverageS2, 
->   currentAverageT3, 
-> FROM 
->   powerLog 
-> WHERE 
->   ts > DATE_SUB(
->     '2020-03-15 18:30:03', INTERVAL 1 MINUTE
->   ) 
->   AND ts < DATE_ADD(
->     '2020-03-15 18:30:03', INTERVAL 1 MINUTE
->   ) 
-> LIMIT 
->   1;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds 
to your MariaDB server version for the right syntax to use near 'FROM 
  powerLog 
WHERE 
  ts > DATE_SUB(
    '2020-03-15 18:30:03', INTERVAL 1 ' at line 5

我可能只是愚蠢，但是...

谢谢 / jon

Answer 1

好像您在FROM语句之前可能会有一个逗号

SELECT 
  currentAverageR1, 
  currentAverageS2, 
  currentAverageT3, <-----
FROM

选择时间跨度，此SQL有什么问题？

1 个答案: