---
title: "ALTER EXTERNAL LIBRARY (Transact-SQL) | Microsoft Docs"
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---
# ALTER EXTERNAL LIBRARY (Transact-SQL)  

[!INCLUDE[tsql-appliesto-ss2017-xxxx-xxxx-xxx-md](../../includes/tsql-appliesto-ss2017-xxxx-xxxx-xxx-md.md)]

Modifies the content of an existing external package library.

## Syntax

```text
ALTER EXTERNAL LIBRARY library_name
[ AUTHORIZATION owner_name ]
SET <file_spec>
WITH ( LANGUAGE = 'R' )
[ ; ]

<file_spec> ::=
{
(CONTENT = { <client_library_specifier> | <library_bits> | NONE}
[, PLATFORM = WINDOWS )
}

<client_library_specifier> :: =
  '[\\computer_name\]share_name\[path\]manifest_file_name'
| '[local_path\]manifest_file_name'
| '<relative_path_in_external_data_source>'

<library_bits> :: =
{ varbinary_literal | varbinary_expression }
```

### Arguments

**library_name**

Specifies the name of an existing package library. Libraries are scoped to the user. Library names are must be unique within the context of a specific user or owner.

The library name cannot be arbitrarily assigned. That is, you must use the name that the calling runtime expects when it loads the package.

**owner_name**

Specifies the name of the user or role that owns the external library.

**file_spec**

Specifies the content of the package for a specific platform. Only one file artifact per platform is supported.

The file can be specified in the form of a local path or network path. If the data source option is specified, the file name can be a relative path with respect to the container referenced in the `EXTERNAL DATA SOURCE`.

Optionally, an OS platform for the file can be specified. Only one file artifact or content is permitted for each OS platform for a specific language or runtime.

**library_bits**

Specifies the content of the package as a hex literal, similar to assemblies. 

This option is useful if you have the required permission to alter a library, but file access on the server is restricted and you cannot save the contents to a path the server can access.

Instead, you can pass the package contents as a variable in binary format.

**PLATFORM = WINDOWS**

Specifies the platform for the content of the library. This value is required when modifying an existing library to add a different platform. Windows is the only supported platform.

## Remarks

For the R language, packages must be prepared in the form of zipped archive files with the .ZIP extension for Windows. Currently, only the Windows platform is supported.  

The `ALTER EXTERNAL LIBRARY` statement only uploads the library bits to the database. The modified library is installed when a user runs code in  [sp_execute_external_script (Transact-SQL)](../../relational-databases/system-stored-procedures/sp-execute-external-script-transact-sql.md) that calls the library.

## Permissions

By default, the **dbo** user or any member of the role **db_owner** has permission to run ALTER EXTERNAL LIBRARY. Additionally, the user who created the external library can alter that external library.

## Examples

The following examples change an external library called `customPackage`.

### A. Replace the contents of a library using a file

The following example modifies an external library called `customPackage`, using a zipped file containing the updated bits.

```sql
ALTER EXTERNAL LIBRARY customPackage 
SET 
  (CONTENT = 'C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\customPackage.zip')
WITH (LANGUAGE = 'R');
```

To install the updated library, execute the stored procedure `sp_execute_external_script`.

```sql
EXEC sp_execute_external_script 
@language =N'R', 
@script=N'library(customPackage)'
;
```

### B. Alter an existing library using a byte stream

The following example alters the existing library by passing the new bits as a hexidecimal literal.

```SQL
ALTER EXTERNAL LIBRARY customLibrary 
SET (CONTENT = 0xabc123) WITH (LANGUAGE = 'R');
```

> [!NOTE]
> This code sample only demonstrates the syntax; the binary value in `CONTENT =` has been truncated for readability and does not create a working library. The actual contents of the binary variable would be much longer.

## See also

[CREATE EXTERNAL LIBRARY (Transact-SQL)](create-external-library-transact-sql.md)
[DROP EXTERNAL LIBRARY (Transact-SQL)](drop-external-library-transact-sql.md)  
[sys.external_library_files](../../relational-databases/system-catalog-views/sys-external-library-files-transact-sql.md)  
[sys.external_libraries](../../relational-databases/system-catalog-views/sys-external-libraries-transact-sql.md)