file-idex-transact-sql.md

description	FILE_IDEX (Transact-SQL)
title	FILE_IDEX (Transact-SQL) | Microsoft Docs
ms.custom
ms.date	03/03/2017
ms.prod	sql
ms.prod_service	sql-database
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ms.technology	t-sql
ms.topic	reference
f1_keywords	FILE_IDEX FILE_IDEX_TSQL
dev_langs	TSQL
helpviewer_keywords	FILE_IDEX function IDs [SQL Server], files file IDs [SQL Server] names [SQL Server], files identification numbers [SQL Server], files file names [SQL Server], FILE_IDEX
ms.assetid	7532fea5-ee5e-4edd-b98b-111a7ba56c8e
author	cawrites
ms.author	chadam

FILE_IDEX (Transact-SQL)

[!INCLUDE SQL Server]

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.

Transact-SQL Syntax Conventions

Syntax

FILE_IDEX ( file_name )  

[!INCLUDEsql-server-tsql-previous-offline-documentation]

Arguments

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

Return Types

int

NULL on error

Remarks

file_name corresponds to the logical file name displayed in the name column from the sys.master_files or sys.database_files catalog views.

Use FILE_IDEX in a SELECT list, a WHERE clause, or anywhere that supports use of an expression. For more information, see Expressions (Transact-SQL).

Examples

A. Retrieving the file id of a specified file

This example returns the file ID for the AdventureWorks_Data file.

USE AdventureWorks2012;  
GO  
SELECT FILE_IDEX('AdventureWorks2012_Data') AS 'File ID';  
GO  

[!INCLUDEssResult]

File ID   
-------   
1  
(1 row(s) affected)  

B. Retrieving the file id when the file name is not known

This example returns the file ID of the AdventureWorks log file. The Transact-SQL (T-SQL) code snippet selects the logical file name from the sys.database_files catalog view, where the file type equals 1 (log).

USE AdventureWorks2012;  
GO  
SELECT FILE_IDEX((SELECT TOP (1) name FROM sys.database_files WHERE type = 1)) AS 'File ID';  
GO  

[!INCLUDEssResult]

File ID   
-------   
2  

C. Retrieving the file id of a full-text catalog file

This example returns the file ID of a full-text file. The T-SQL code snippet selects the logical file name from the sys.database_files catalog view, where the file type equals 4 (full-text). This code returns 'NULL' if a full-text catalog does not exist.

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

See Also

Metadata Functions (Transact-SQL)
sys.database_files (Transact-SQL)
sys.master_files (Transact-SQL)