Indicates whether a SQL Server login is a member of the specified server role.
Use IS_SRVROLEMEMBER to determine whether the current user can perform an action requiring the server role's permissions.
If a Windows login, such as Contoso\Mary5, is specified for login, IS_SRVROLEMEMBER returns NULL, unless the login has been granted or denied direct access to SQL Server.
If the optional login parameter is not provided and if login is a Windows domain login, it may be a member of a fixed server role through membership in a Windows group. To resolve such indirect memberships, IS_SRVROLEMEMBER requests Windows group membership information from the domain controller. If the domain controller is inaccessible or does not respond, IS_SRVROLEMEMBER returns role membership information by accounting for the user and its local groups only. If the user specified is not the current user, the value returned by IS_SRVROLEMEMBER might differ from the authenticator's (such as Active Directory) last data update to SQL Server.
If the optional login parameter is provided, the Windows login that is being queried must be present in sys.server_principals, or IS_SRVROLEMEMBER will return NULL. This indicates that the login is not valid.
When the login parameter is a domain login or based on a Windows group and the domain controller is inaccessible, calls to IS_SRVROLEMEMBER will fail and might return incorrect or incomplete data.
If the domain controller is not available, the call to IS_SRVROLEMEMBER will return accurate information when the Windows principle can be authenticated locally, such as a local Windows account or a SQL Server login.
IS_SRVROLEMEMBER always returns 0 when a Windows group is used as the login argument, and this Windows group is a member of another Windows group which is, in turn, a member of the specified server role.
The User Account Control (UAC) found in Windows Vista and Windows Server 2008 might also return different results. This would depend on whether the user accessed the server as a Windows group member or as a specific SQL Server user.
This function evaluates role membership, not the underlying permission. For example, the sysadmin fixed server role has the CONTROL SERVER permission. If the user has the CONTROL SERVER permission but is not a member of the role, this function will correctly report that the user is not a member of the sysadmin role, even though the user has the same permissions.
The following example indicates whether the SQL Server login for the current user is a member of the sysadmin fixed server role.
IF IS_SRVROLEMEMBER ('sysadmin') = 1 print 'Current user''s login is a member of the sysadmin role' ELSE IF IS_SRVROLEMEMBER ('sysadmin') = 0 print 'Current user''s login is NOT a member of the sysadmin role' ELSE IF IS_SRVROLEMEMBER ('sysadmin') IS NULL print 'ERROR: The server role specified is not valid.'