--- title: sum() function description: > `sum()` returns the sum of non-null values in a specified column. menu: flux_v0_ref: name: sum parent: universe identifier: universe/sum weight: 101 flux/v0/tags: [transformations, aggregates] introduced: 0.7.0 --- `sum()` returns the sum of non-null values in a specified column. ##### Function type signature ```js (<-tables: stream[A], ?column: string) => stream[B] where A: Record, B: Record ``` {{% caption %}} For more information, see [Function type signatures](/flux/v0/function-type-signatures/). {{% /caption %}} ## Parameters ### column Column to operate on. Default is `_value`. ### tables Input data. Default is piped-forward data (`<-`). ## Examples ### Return the sum of values in each table ```js import "sampledata" sampledata.int() |> sum() ``` {{< expand-wrapper >}} {{% expand "View example input and output" %}} #### Input data | _time | _value | *tag | | -------------------- | ------- | ---- | | 2021-01-01T00:00:00Z | -2 | t1 | | 2021-01-01T00:00:10Z | 10 | t1 | | 2021-01-01T00:00:20Z | 7 | t1 | | 2021-01-01T00:00:30Z | 17 | t1 | | 2021-01-01T00:00:40Z | 15 | t1 | | 2021-01-01T00:00:50Z | 4 | t1 | | _time | _value | *tag | | -------------------- | ------- | ---- | | 2021-01-01T00:00:00Z | 19 | t2 | | 2021-01-01T00:00:10Z | 4 | t2 | | 2021-01-01T00:00:20Z | -3 | t2 | | 2021-01-01T00:00:30Z | 19 | t2 | | 2021-01-01T00:00:40Z | 13 | t2 | | 2021-01-01T00:00:50Z | 1 | t2 | #### Output data | *tag | _value | | ---- | ------- | | t1 | 51 | | *tag | _value | | ---- | ------- | | t2 | 53 | {{% /expand %}} {{< /expand-wrapper >}}