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    Time Series Database:ORDER BY time DESC

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    Time Series Database:ORDER BY time DESC

    Last Updated:Sep 11, 2020

    By default, TSDB for InfluxDB® returns results based on timestamps in ascending order. The first returned point is attached with the earliest timestamp and the last returned point is attached with the latest timestamp. ORDER BY time DESC reverses the default timestamp order so that TSDB for InfluxDB® returns the points that are attached with the latest timestamp.

    Syntax

    1. SELECT_clause [INTO_clause] FROM_clause [WHERE_clause] [GROUP_BY_clause] ORDER BY time DESC

    Description

    If a query includes a GROUP BY clause, the ORDER BY time DESC clause must appear after the GROUP BY clause. If a query includes a WHERE clause and no GROUP BY clause, the ORDER BY time DESC clause must appear after the WHERE clause.

    Examples

    Obtain points based on timestamps in descending order

    1. > SELECT "water_level" FROM "h2o_feet" WHERE "location" = 'santa_monica' ORDER BY time DESC
    3. name: h2o_feet
    4. time                   water_level
    5. ----                   -----------
    6. 2015-09-18T21:42:00Z   4.938
    7. 2015-09-18T21:36:00Z   5.066
    8. [...]
    9. 2015-08-18T00:06:00Z   2.116
    10. 2015-08-18T00:00:00Z   2.064

    The query returns the points from the h2o_feet measurement based on timestamps in descending order. The first returned point is attached with the latest timestamp. If the preceding statement does not include ORDER by time DESC, the query returns the points based on timestamps in ascending order. The first returned point is attached with the earliest timestamp 2015-08-18T00:00:00Z. The last returned point is attached with the latest timestamp 2015-09-18T21:42:00Z.

    Obtain points based on timestamps in descending order and include a GROUP BY time() clause

    1. > SELECT MEAN("water_level") FROM "h2o_feet" WHERE time >= '2015-08-18T00:00:00Z' AND time <= '2015-08-18T00:42:00Z' GROUP BY time(12m) ORDER BY time DESC
    3. name: h2o_feet
    4. time                   mean
    5. ----                   ----
    6. 2015-08-18T00:36:00Z   4.6825
    7. 2015-08-18T00:24:00Z   4.80675
    8. 2015-08-18T00:12:00Z   4.950749999999999
    9. 2015-08-18T00:00:00Z   5.07625

    The query uses an InfluxQL function and a time interval specified by the GROUP BY clause to calculate the average field value of the water_level field key for each 12-minute interval in the specified time range. The first result returned by the ORDER BY time DESC clause corresponds to the latest 12-minute interval. If the preceding statement does not include ORDER by time DESC, the query returns the points based on timestamps in ascending order. The first returned point is attached with the earliest timestamp 2015-08-18T00:00:00Z. The last returned point is attached with the latest timestamp 2015-08-18T00:36:00Z.


    InfluxDB® is a trademark registered by InfluxData, which is not affiliated with, and does not endorse, TSDB for InfluxDB®.