Query first and last values

Use the first() or last() functions 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:

The following function returns:

|> first()

last

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

Given the following input:

The following function returns:

|> last()

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:

The following function returns:

first last

|> aggregateWindow(
  every: 1h,
  fn: first
)

|> aggregateWindow(
  every: 1h,
  fn: last
)

Related articles

• first() function
• last() function

query