Documentation

InfluxQL miscellaneous functions

Limited availability

InfluxDB Clustered is currently only available to a limited group of InfluxData customers. If interested in being part of the limited access group, please contact the InfluxData Sales team.

Use InfluxQL miscellaneous functions to perform different operations in InfluxQL queries.

fill()

Fills null field values returned from empty time windows in GROUP BY time() queries with a specified fill value.

Supported only in the GROUP BY clause.

fill(behavior)

Arguments

  • behavior: Defines the behavior of the fill operation. If no FILL clause is included, the default behavior is fill(null).

    The following options are available:

    • numeric literal: Replaces null values with the specified numeric literal.
    • linear: Uses linear interpolation between existing values to replace null values.
    • none: Removes rows with null field values.
    • null: Keeps null values and associated timestamps.
    • previous: Replaces null values with the most recent non-null value.

Examples

The following example uses the Bitcoin price sample dataset.

SELECT
  MEAN(price)
FROM bitcoin
WHERE
  code = 'USD'
  AND time >= '2023-05-01T00:00:00Z'
  AND time < '2023-05-01T02:00:00Z'
GROUP BY
  time(30m)
  fill(0)

name: bitcoin

time mean
2023-05-01T00:00:00Z 29319.9092
2023-05-01T00:30:00Z 29307.4416
2023-05-01T01:00:00Z 0
2023-05-01T01:30:00Z 29263.2886
SELECT
  MEAN(price)
FROM bitcoin
WHERE
  code = 'USD'
  AND time >= '2023-05-01T00:00:00Z'
  AND time < '2023-05-01T02:00:00Z'
GROUP BY
  time(30m)
  fill(linear)

name: bitcoin

time mean
2023-05-01T00:00:00Z 29319.9092
2023-05-01T00:30:00Z 29307.4416
2023-05-01T01:00:00Z 29285.3651
2023-05-01T01:30:00Z 29263.2886
SELECT
  MEAN(price)
FROM bitcoin
WHERE
  code = 'USD'
  AND time >= '2023-05-01T00:00:00Z'
  AND time < '2023-05-01T02:00:00Z'
GROUP BY
  time(30m)
  fill(none)

name: bitcoin

time mean
2023-05-01T00:00:00Z 29319.9092
2023-05-01T00:30:00Z 29307.4416
2023-05-01T01:30:00Z 29263.2886
SELECT
  MEAN(price)
FROM bitcoin
WHERE
  code = 'USD'
  AND time >= '2023-05-01T00:00:00Z'
  AND time < '2023-05-01T02:00:00Z'
GROUP BY
  time(30m)
  fill(null)

name: bitcoin

time mean
2023-05-01T00:00:00Z 29319.9092
2023-05-01T00:30:00Z 29307.4416
2023-05-01T01:00:00Z
2023-05-01T01:30:00Z 29263.2886
SELECT
  MEAN(price)
FROM bitcoin
WHERE
  code = 'USD'
  AND time >= '2023-05-01T00:00:00Z'
  AND time < '2023-05-01T02:00:00Z'
GROUP BY
  time(30m)
  fill(previous)

name: bitcoin

time mean
2023-05-01T00:00:00Z 29319.9092
2023-05-01T00:30:00Z 29307.4416
2023-05-01T01:00:00Z 29307.4416
2023-05-01T01:30:00Z 29263.2886

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Introducing InfluxDB Clustered

A highly available InfluxDB 3.0 cluster on your own infrastructure.

InfluxDB Clustered is a highly available InfluxDB 3.0 cluster built for high write and query workloads on your own infrastructure.

InfluxDB Clustered is currently in limited availability and is only available to a limited group of InfluxData customers. If interested in being part of the limited access group, please contact the InfluxData Sales team.

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The future of Flux

Flux is going into maintenance mode. You can continue using it as you currently are without any changes to your code.

Flux is going into maintenance mode and will not be supported in InfluxDB 3.0. This was a decision based on the broad demand for SQL and the continued growth and adoption of InfluxQL. We are continuing to support Flux for users in 1.x and 2.x so you can continue using it with no changes to your code. If you are interested in transitioning to InfluxDB 3.0 and want to future-proof your code, we suggest using InfluxQL.

For information about the future of Flux, see the following: