arg_min() (aggregation function)

Finds a row in the table that minimizes the specified expression. It returns all columns of the input table or specified columns.

Syntax

arg_min (ExprToMinimize, * | ExprToReturn [, …])

Parameters

Null handling

When ExprToMinimize is null for all rows in a table, one row in the table is picked. Otherwise, rows where ExprToMinimize is null are ignored.

Returns

Returns a row in the table that minimizes ExprToMinimize, and the values of columns specified in ExprToReturn. Use or * to return the entire row.

Examples

Find the minimum latitude of a storm event in each state.

StormEvents 
| summarize arg_min(BeginLat, BeginLocation) by State

Output

The results table shown includes only the first 10 rows.

Find the first time an event with a direct death happened in each state, showing all of the columns.

The query first filters the events to only include those where there was at least one direct death. Then the query returns the entire row with the lowest value for StartTime.

StormEvents
| where DeathsDirect > 0
| summarize arg_min(StartTime, *) by State

Output

The results table shown includes only the first 10 rows and first 3 columns.

The following example demonstrates null handling.

datatable(Fruit: string, Color: string, Version: int) [
    "Apple", "Red", 1,
    "Apple", "Green", int(null),
    "Banana", "Yellow", int(null),
    "Banana", "Green", int(null),
    "Pear", "Brown", 1,
    "Pear", "Green", 2,
]
| summarize arg_min(Version, *) by Fruit

Output

Comparison to min()

The arg_min() function differs from the min() function. The arg_min() function allows you to return additional columns along with the minimum value, and min() only returns the minimum value itself.

Examples

arg_min()

Find the first time an event with a direct death happened, showing all the columns in the table.

The query first filters the events to only include those where there was at least one direct death. Then the query returns the entire row with the lowest value for StartTime.

StormEvents
| where DeathsDirect > 0
| summarize arg_min(StartTime, *)

The results table returns all the columns for the row containing the lowest value in the expression specified.

| StartTime | EndTime | EpisodeId | EventId | State | EventType | … | |–|–|–|–| | 2007-01-01T00:00:00Z | 2007-01-22T18:49:00Z | 2408 | 11929 | INDIANA | Flood | … |

min()

Find the first time an event with a direct death happened.

The query filters events to only include those where there is at least one direct death, and then returns the minimum value for StartTime.

StormEvents
| where DeathsDirect > 0
| summarize min(StartTime)

The results table returns the lowest value in the specific column only.

Related content

• min function
• max function
• avg function
• percentile function
• min-of function