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title: "FILE_IDEX (Transact-SQL) | Microsoft Docs"
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---
# FILE_IDEX (Transact-SQL)
[!INCLUDE[tsql-appliesto-ss2008-xxxx-xxxx-xxx-md](../../includes/tsql-appliesto-ss2008-xxxx-xxxx-xxx-md.md)]

Returns the file identification (ID) number for the specified logical file name of the data, log, or full-text file in the current database.  
  
![Topic link icon](../../database-engine/configure-windows/media/topic-link.gif "Topic link icon") [Transact-SQL Syntax Conventions](../../t-sql/language-elements/transact-sql-syntax-conventions-transact-sql.md)  
  
## Syntax  
  
```  
FILE_IDEX ( file_name )  
```  
  
## Arguments  
 *file_name*  
 Is an expression of type **sysname** that represents the name of the file for which to return the file ID.  
  
## Return Types  
 **int**  
  
 **NULL** on error  
  
## Remarks  
 *file_name* corresponds to the logical file name displayed in the **name** column in the [sys.master_files](../../relational-databases/system-catalog-views/sys-master-files-transact-sql.md) or [sys.database_files](../../relational-databases/system-catalog-views/sys-database-files-transact-sql.md) catalog views.  
  
 FILE_IDEX can be used in a select list, a WHERE clause, or anywhere an expression is allowed. For more information, see [Expressions (Transact-SQL)](../../t-sql/language-elements/expressions-transact-sql.md).  
  
## Examples  
  
### A. Retrieving the file id of a specified file  
The following example returns the file ID for the `AdventureWorks_Data` file.  
  
```sql  
USE AdventureWorks2012;  
GO  
SELECT FILE_IDEX('AdventureWorks2012_Data') AS 'File ID';  
GO  
```  
  
 [!INCLUDE[ssResult](../../includes/ssresult-md.md)]  
  
```  
File ID   
-------   
1  
(1 row(s) affected)  
```  
  
### B. Retrieving the file id when the file name is not known  
The following example returns the file ID of the `AdventureWorks` log file by selecting the logical file name from the `sys.database_files` catalog view where the file type is equal to `1` (log).  
  
```sql  
USE AdventureWorks2012;  
GO  
SELECT FILE_IDEX((SELECT TOP (1) name FROM sys.database_files WHERE type = 1)) AS 'File ID';  
GO  
```  
  
 [!INCLUDE[ssResult](../../includes/ssresult-md.md)]  
  
```  
File ID   
-------   
2  
```  
  
### C. Retrieving the file id of a full-text catalog file  
The following example returns the file ID of a full-text file by selecting the logical file name from the `sys.database_files` catalog view where the file type is equal to `4` (full-text). This example will return NULL if a full-text catalog does not exist.  
  
```sql  
SELECT FILE_IDEX((SELECT name FROM sys.master_files WHERE type = 4))  
AS 'File_ID';  
```  
  
## See Also  
 [Metadata Functions (Transact-SQL)](../../t-sql/functions/metadata-functions-transact-sql.md)   
 [sys.database_files (Transact-SQL)](../../relational-databases/system-catalog-views/sys-database-files-transact-sql.md)   
 [sys.master_files (Transact-SQL)](../../relational-databases/system-catalog-views/sys-master-files-transact-sql.md)