IS_OBJECTSIGNED (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Indicates whether an object is signed by a specified certificate or asymmetric key.
Transact-SQL syntax conventions
Syntax
IS_OBJECTSIGNED (
'OBJECT', @object_id, @class, @thumbprint
)
Arguments
'OBJECT'
The type of securable class.
@object_id
The object_id of the object being tested. @object_id is type int.
@class
The class of the object:
'certificate'
'asymmetric key'
@class is sysname.
@thumbprint
The SHA thumbprint of the object. @thumbprint is type varbinary(32).
Returned Types
int
Remarks
IS_OBJECTSIGNED returns the following values.
| Return value | Description |
|---|---|
| NULL | The object is not signed, or the object is not valid. |
| 0 | The object is signed, but the signature is not valid. |
| 1 | The object is signed. |
Permissions
Requires VIEW DEFINITION on the certificate or asymmetric key.
Examples
A. Displaying extended properties on a database
The following example tests if the spt_fallback_db table in the master database is signed by the schema signing certificate.
USE master;
-- Declare a variable to hold a thumbprint and an object name
DECLARE @thumbprint varbinary(20), @objectname sysname;
-- Populate the thumbprint variable with the thumbprint of
-- the master database schema signing certificate
SELECT @thumbprint = thumbprint
FROM sys.certificates
WHERE name LIKE '%SchemaSigningCertificate%';
-- Populate the object name variable with a table name in master
SELECT @objectname = 'spt_fallback_db';
-- Query to see if the table is signed by the thumbprint
SELECT @objectname AS [object name],
IS_OBJECTSIGNED(
'OBJECT', OBJECT_ID(@objectname), 'certificate', @thumbprint
) AS [Is the object signed?] ;