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edit-distance-transact-sql.md

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title EDIT_DISTANCE (Transact-SQL)
description EDIT_DISTANCE calculates the number of insertions, deletions, substitutions, and transpositions needed to transform one string to another.
author MikeRayMSFT
ms.author mikeray
ms.reviewer abhtiwar, wiassaf, randolphwest
ms.date 11/18/2025
ms.service sql
ms.subservice t-sql
ms.topic reference
ms.custom
ignite-2025
dev_langs
TSQL
monikerRange =azuresqldb-current || =azuresqldb-mi-current || =fabric-sqldb || >=sql-server-2016

EDIT_DISTANCE (Transact-SQL) preview

[!INCLUDE sqlserver2025-asdb-asmi-fabricsqldb]

[!INCLUDE preview]

Calculates the distance that is the number of insertions, deletions, substitutions, and transpositions needed to transform one string to another.

Note

  • EDIT_DISTANCE is in preview.
  • EDIT_DISTANCE currently doesn't support transpositions.
  • SQL Server support for EDIT_DISTANCE introduced in [!INCLUDE sssql25-md].
  • EDIT_DISTANCE is available in Azure SQL Managed Instance with the SQL Server 2025 or Always-up-to-date update policy.

Syntax

EDIT_DISTANCE (
    character_expression
    , character_expression [ , maximum_distance ]
)

Arguments

character_expression

An alphanumeric expression of character data. character_expression can be a constant, variable, or column. The character expression can't be of type varchar(max) or nvarchar(max).

maximum_distance

The maximum distance that should be computed. maximum_distance is an integer. If greater than or equal to zero, then the function stops calculating the distance when the maximum_distance is reached.

Return value

int

Returns the distance between the two character_expressions using Damerau-Levenshtein algorithm, or maximum_distance value if that is smaller. If any of the inputs is NULL then the function returns a NULL value.

Remarks

If the actual distance is greater than maximum_distance, then the function might return a value greater than or equal to maximum_distance.

Examples

Example 1

The following example compares two words and returns the EDIT_DISTANCE() value as a column, named Distance.

SELECT 'Colour' AS WordUK,
       'Color' AS WordUS,
       EDIT_DISTANCE('Colour', 'Color') AS Distance;

Returns:

WordUK WordUS Distance
------ ------ -----------
Colour Color  1

Example 2

The following example compares two words and returns the EDIT_DISTANCE() limited to a maximum value.

SELECT Source, Target,
	   EDIT_DISTANCE(Source, Target) AS ActualDistance,
       EDIT_DISTANCE(Source, Target,2) AS LimitedDistance
FROM (VALUES('Chocolate', 'Sweets')) compare(Source, Target) ;

Returns:

Source    Target    ActualDistance LimitedDistance
--------- --------- -------------- ---------------
Chocolate Sweets    8              2

For additional examples, see Example EDIT_DISTANCE().

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