FILE_IDEX()

This function returns the file identification (ID) number for the specified logical name of a data, log, or full-text file of the current database.

Signature

FILE_IDEX ( file_name )

Parameters

file_name — An expression of type sysname that returns the file ID value 'FILE_IDEX' for the name of the file.

Examples

SELECT FILE_IDEX((SELECT name FROM sys.master_files WHERE type = 4))  
AS 'File_ID';

NULL

Run against SQL Server 16.0.4265.3 on 2026-09-13. This is the output we got, not the documentation’s.

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