set_union()

Switch services using the Version drop-down list. Learn more about navigation.
Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Returns a dynamic array of the set of all distinct values that are in any of the arrays - (arr1 ∪ arr2 ∪ ...).

Syntax

set_union(set1, set2 [, set3, ...])

Learn more about syntax conventions.

Parameters

Name	Type	Required	Description
set1...setN	dynamic	✔️	Arrays used to create a union set. A minimum of two arrays are required. See pack_array.

Returns

Returns a dynamic array of the set of all distinct values that are in any of arrays.

Example

Set from multiple dynamic array

Run the query

range x from 1 to 3 step 1
| extend y = x * 2
| extend z = y * 2
| extend w = z * 2
| extend a1 = pack_array(x,y,x,z), a2 = pack_array(x, y), a3 = pack_array(w)
| project a1,a2,a3,Out=set_union(a1, a2, a3)

Output

a1	a2	a3	Out
[1,2,1,4]	[1,2]	[8]	[1,2,4,8]
[2,4,2,8]	[2,4]	[16]	[2,4,8,16]
[3,6,3,12]	[3,6]	[24]	[3,6,12,24]

Set from one dynamic array

Run the query

datatable (Arr1: dynamic)
[
    dynamic(['A4', 'A2', 'A7', 'A2']), 
    dynamic(['C4', 'C7', 'C1', 'C4'])
] 
| extend Out=set_union(Arr1, Arr1)

Output

Arr1	Out
["A4","A2","A7","A2"]	["A4","A2","A7"]
["C4","C7","C1","C4"]	["C4","C7","C1"]

Related content

• set_intersect()
• set_difference()