Error "Unknown Function" When Using REGEXP Functions on a Microsoft SQL Server Data Source

Published: 10 Oct 2017
Last Modified Date: 26 Nov 2019


When using a REGEXP_EXTRACT function on a Microsoft SQL Server data source, the following error might occur: 

"Unknown Function"


  • Tableau Desktop 10.4
  • Windows 7
  • MS SQL Server


Option 1

Add your vote to this idea for Microsoft SQL Server: Regex functionality in pattern matching.

Option 2

As a workaround, try leveraging RawSQL to pass-in functions that the data source supports (note that this will depend on what you wish to accomplish with the substring from the REGEXP function): Pass-Through Functions (RAWSQL).


Support for regular expressions is not currently built into Microsoft SQL Server.
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