in operator

Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Filters a record set for data with a case-sensitive string.

The following table provides a comparison of the in operators:

Operator	Description	Case-Sensitive	Example (yields true)
in	Equals to one of the elements	Yes	"abc" in ("123", "345", "abc")
!in	Not equals to any of the elements	Yes	"bca" !in ("123", "345", "abc")
in~	Equals to any of the elements	No	"Abc" in~ ("123", "345", "abc")
!in~	Not equals to any of the elements	No	"bCa" !in~ ("123", "345", "ABC")

Note

Nested arrays are flattened into a single list of values. For example, x in (dynamic([1,[2,3]])) becomes x in (1,2,3).

For further information about other operators and to determine which operator is most appropriate for your query, see datatype string operators.

Case-insensitive operators are currently supported only for ASCII-text. For non-ASCII comparison, use the tolower() function.

Performance tips

Note

Performance depends on the type of search and the structure of the data. For best practices, see Query best practices.

Syntax

T | where col in (expression, ... )

Learn more about syntax conventions.

Parameters

Name	Type	Required	Description
T	string	✔️	The tabular input to filter.
col	string	✔️	The column by which to filter.
expression	scalar or tabular	✔️	An expression that specifies the values for which to search. the values for which to search. Each expression can be a scalar value or a tabular expression that produces a set of values. If a tabular expression has multiple columns, the first column is used. The search will consider up to 1,000,000 distinct values.

Note

An inline tabular expression must be enclosed with double parentheses. See example.

Returns

Rows in T for which the predicate is true.

Examples

List of scalars

The following query shows how to use in with a list of scalar values.

Run the query

StormEvents 
| where State in ("FLORIDA", "GEORGIA", "NEW YORK") 
| count

Output

Count
4775

Dynamic array

The following query shows how to use in with a dynamic array.

Run the query

let states = dynamic(['FLORIDA', 'ATLANTIC SOUTH', 'GEORGIA']);
StormEvents 
| where State in (states)
| count

Output

Count
3218

Tabular expression

The following query shows how to use in with a tabular expression.

Run the query

let Top_5_States = 
    StormEvents
    | summarize count() by State
    | top 5 by count_; 
StormEvents 
| where State in (Top_5_States) 
| count

The same query can be written with an inline tabular expression statement.

Run the query

StormEvents 
| where State in (
    StormEvents
    | summarize count() by State
    | top 5 by count_
    ) 
| count

Output

Count
14242

Top with other example

Run the query

let Lightning_By_State = materialize(StormEvents
    | summarize lightning_events = countif(EventType == 'Lightning') by State);
let Top_5_States = Lightning_By_State | top 5 by lightning_events | project State; 
Lightning_By_State
| extend State = iff(State in (Top_5_States), State, "Other")
| summarize sum(lightning_events) by State 

Output

State	sum_lightning_events
ALABAMA	29
WISCONSIN	31
TEXAS	55
FLORIDA	85
GEORGIA	106
Other	415

Use a static list returned by a function

Run the query

StormEvents 
| where State in (InterestingStates()) 
| count

Output

Count
4775

The function definition.

Run the query

.show function InterestingStates

Output

Name	Parameters	Body	Folder	DocString
InterestingStates	()	{ dynamic(["WASHINGTON", "FLORIDA", "GEORGIA", "NEW YORK"]) }