---
title: "sys.assemblies (Transact-SQL) | Microsoft Docs"
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ms.date: "03/14/2017"
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- "sys.assemblies"
- "assemblies_TSQL"
- "sys.assemblies_TSQL"
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- "sys.assemblies catalog view"
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---
# sys.assemblies (Transact-SQL)
[!INCLUDE[tsql-appliesto-ss2008-xxxx-asdw-pdw-md](../../includes/tsql-appliesto-ss2008-xxxx-asdw-pdw-md.md)]
Returns a row for each assembly.
|Column name|Data type|Description|
|-----------------|---------------|-----------------|
|**name**|**sysname**|Name of the assembly. Is unique within the database.|
|**principal_id**|**int**|ID of the principal that owns this assembly.|
|**assembly_id**|**int**|Assembly identification number. Is unique within a database.|
|**clr_name**|**nvarchar(4000)**|Canonical string that encodes the simple name, version number, culture, public key, and architecture of the assembly. This value uniquely identifies the assembly on the common language runtime (CLR) side.|
|**permission_set**|**tinyint**|Permission-set/security-level for assembly.
1 = Safe Access
2 = External Access
3 = Unsafe Access|
|**permission_set_desc**|**nvarchar(60)**|Description for permission-set/security-level for assembly.
SAFE_ACCESS
EXTERNAL_ACCESS
UNSAFE_ACCESS|
|**is_visible**|**bit**|1 = Assembly is visible to register [!INCLUDE[tsql](../../includes/tsql-md.md)] entry points.
0 = Assembly is intended only for managed callers. That is, the assembly provides internal implementation for other assemblies in the database.|
|**create_date**|**datetime**|Date the assembly was created or registered.|
|**modify_date**|**datetime**|Date the assembly was modified.|
|**is_user_defined**|**bit**|Indicates the source of the assembly.
0 = System-defined assemblies (such as Microsoft.SqlServer.Types for the **hierarchyid** data type)
1 = User-defined assemblies|
## Permissions
[!INCLUDE[ssCatViewPerm](../../includes/sscatviewperm-md.md)] For more information, see [Metadata Visibility Configuration](../../relational-databases/security/metadata-visibility-configuration.md).
## See Also
[CLR Assembly Catalog Views (Transact-SQL)](../../relational-databases/system-catalog-views/clr-assembly-catalog-views-transact-sql.md)
[Catalog Views (Transact-SQL)](../../relational-databases/system-catalog-views/catalog-views-transact-sql.md)
[ASSEMBLYPROPERTY (Transact-SQL)](../../t-sql/functions/assemblyproperty-transact-sql.md)