Are these functions available in SQL Server 2012 or older?
select IS_ROLEMEMBER ('db_owner');
select IS_SRVROLEMEMBER ('sysadmin');
I can not find any compatibility information in the online documentation here: https://learn.microsoft.com/en-us/sql/t-sql/functions/is-rolemember-transact-sql?view=sql-server-ver15
Is_RoleMember was introduced in SQL Server 2012.
Is_SrvRoleMember was introduced in SQL Server 2005 itself.
You can see when a particular feature was introduced by going through below links. These changes are coming under Database Engine Enhancements => Database Engine Security Enhancements
To see all the historical information about SQL Server versions, below link is very helpful: https://www.sqlshack.com/history-sql-server-evolution-sql-server-features/