mv-expand

Expands multi-value dynamic arrays or property bags into multiple rows, duplicating other columns.

Expands multi-value dynamic arrays or property bags into multiple rows, duplicating other columns. Tip: if you only need to filter rows where any array element matches a condition, use the wildcard array access syntax instead — e.g. where events[*].name == "error" — which avoids expanding rows.

Syntax

mv-expand column

Expand array column into rows

Parameters

Name	Description
column	Column containing dynamic array to expand

Syntax

mv-expand column to typeof(type)

Expand with type conversion

Parameters

Name	Description
column	Column containing dynamic array to expand
type	Type to cast expanded values to

Examples

Example 1

datatable(ship:string, cargo:dynamic)[
  "Naglfar", dynamic(["silver", "gold", "amber"]),
  "Wave Rider", dynamic(["furs", "ivory"])
]
| mv-expand cargo

ship (string)	cargo (dynamic)
Naglfar	"amber"
Naglfar	"gold"
Naglfar	"silver"
Wave Rider	"furs"
Wave Rider	"ivory"

Example 2

datatable(jarl:string, raids:dynamic)[
  "Erik", dynamic([100, 250, 50]),
  "Olaf", dynamic([300, 150])
]
| mv-expand raids to typeof(long)

jarl (string)	raids (long)
Erik	100
Erik	250
Erik	50
Olaf	150
Olaf	300

Example 3

datatable(warrior:string, weapons:dynamic)[
  "Ragnar", dynamic(["axe", "shield", "seax"]),
  "Lagertha", dynamic(["spear", "shield"])
]
| mv-expand weapons
| summarize count() by tostring(weapons)

weapons (string)	count_ (long)
axe	1
seax	1
shield	2
spear	1

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