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Query first and last values

This page documents an earlier version of InfluxDB. InfluxDB v2.6 is the latest stable version. View this page in the v2.6 documentation.

Use first() or last() to return the first or last record in an input table.

data
    |> first()

// OR

data
    |> last()

By default, InfluxDB returns results sorted by time, however you can use the sort() function to change how results are sorted. first() and last() respect the sort order of input data and return records based on the order they are received in.

first

first() returns the first non-null record in an input table.

Given the following input:

_time_value
2020-01-01T00:01:00Z1.0
2020-01-01T00:02:00Z1.0
2020-01-01T00:03:00Z2.0
2020-01-01T00:04:00Z3.0

The following function returns:

|> first()
_time_value
2020-01-01T00:01:00Z1.0

last

last() returns the last non-null record in an input table.

Given the following input:

_time_value
2020-01-01T00:01:00Z1.0
2020-01-01T00:02:00Z1.0
2020-01-01T00:03:00Z2.0
2020-01-01T00:04:00Z3.0

The following function returns:

|> last()
_time_value
2020-01-01T00:04:00Z3.0

Use first() or last() with aggregateWindow()

Use first() and last() with aggregateWindow() to select the first or last records in time-based groups. aggregateWindow() segments data into windows of time, aggregates data in each window into a single point using aggregate or selector functions, and then removes the time-based segmentation.

Given the following input:

_time_value
2020-01-01T00:00:00Z10
2020-01-01T00:00:15Z12
2020-01-01T00:00:45Z9
2020-01-01T00:01:05Z9
2020-01-01T00:01:10Z15
2020-01-01T00:02:30Z11

The following function returns:

|> aggregateWindow(every: 1h, fn: first)
_time_value
2020-01-01T00:00:59Z10
2020-01-01T00:01:59Z9
2020-01-01T00:02:59Z11
|> aggregateWindow(every: 1h, fn: last)
_time_value
2020-01-01T00:00:59Z9
2020-01-01T00:01:59Z15
2020-01-01T00:02:59Z11

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For more information, see the Linux Package Signing Key Rotation blog post.

InfluxDB Cloud backed by InfluxDB IOx

All InfluxDB Cloud organizations created on or after January 31, 2023 are backed by the new InfluxDB IOx storage engine. Check the right column of your InfluxDB Cloud organization homepage to see which InfluxDB storage engine you’re using.

If powered by IOx, this is the correct documentation.

If powered by TSM, see the TSM-based InfluxDB Cloud documentation.

InfluxDB Cloud backed by InfluxDB TSM

All InfluxDB Cloud organizations created on or after January 31, 2023 are backed by the new InfluxDB IOx storage engine which enables nearly unlimited series cardinality and SQL query support. Check the right column of your InfluxDB Cloud organization homepage to see which InfluxDB storage engine you’re using.

If powered by TSM, this is the correct documentation.

If powered by IOx, see the IOx-based InfluxDB Cloud documentation.

State of the InfluxDB Cloud (IOx) documentation

The new documentation for InfluxDB Cloud backed by InfluxDB IOx is a work in progress. We are adding new information and content almost daily. Thank you for your patience!

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