Levenshtein Distance Function

[XinyuTan]

Our current SQL server 2017 doesn't have built-in function for calculating Levenshtein distance.  I know Microsoft has that function somewhere.  How can we obtain such built-in function from Microsoft?

Thanks,

Justin

[#2]

@XinyuTan 

Hey, Justin.

It doesn't exist in SQL Server (deliberately excluding Master Data Services), but you can achieve a similar outcome using DIFFERENCE:

• DIFFERENCE (Transact-SQL) - SQL Server | Microsoft Learn
• How to add Percentage of similar compare two string ? - Microsoft Q&A

You could look at authoring your own SQL CLR-based function using the Spark library, but this isn't particularly portable since you cannot add CLR-based functions to the more affordable Azure SQL options (only Azure SQL MI can handle CLR functions):

• Create CLR Functions - SQL Server | Microsoft Learn
• It's just SQL: CLR in Azure SQL Database Managed Instance | Microsoft Learn
• Functions.Levenshtein(Column, Column) Method (Microsoft.Spark.Sql) - .NET for Apache Spark | Microso...

Cheers,

Lain

[#3]

@LainRobertson 

Lain,

Thank you for the explanations and those reference links!

Justin

[#4]

@XinyuTan 

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Our current SQL server 2017 doesn't have built-in function for calculating Levenshtein distance. 

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No version of SQL Server do have the Levenshtein distance algorythm as build-in function, you have to implement it on your own.

I know Microsoft has that function somewhere.

No, not for SQL Server, only in the Cloud

levenshtein function - Azure Databricks - Databricks SQL | Microsoft Learn