make_list_with_nulls() (aggregation function)

Learn how to use the make_list_with_nulls() aggregation function to create a dynamic JSON object (array) which includes null values.

Creates a dynamic array of all the values of expr in the group, including null values.

Syntax

make_list_with_nulls(expr)

Parameters

NameTypeRequiredDescription
exprstring✔️The expression that to use to create the array.

Returns

Returns a dynamic JSON object (array) of all the values of expr in the group, including null values. If the input to the summarize operator isn’t sorted, the order of elements in the resulting array is undefined. If the input to the summarize operator is sorted, the order of elements in the resulting array tracks that of the input.

Example

The following example shows null values in the results.

let shapes = datatable (name:string , sideCount: int)
[
    "triangle", int(null),
    "square", 4,
    "rectangle", 4,
    "pentagon", 5,
    "hexagon", 6,
    "heptagon", 7,
    "octagon", 8,
    "nonagon", 9,
    "decagon", 10
];
shapes
| summarize mylist = make_list_with_nulls(sideCount)

Output

mylist
[null,4,4,5,6,7,8,9,10]