Simulating an EXISTS Clause in a Natively Compiled Stored Procedure
Natively compiled stored procedures do not support the EXISTS
clause, but there is a workaround:
DECLARE @exists BIT = 0
SELECT TOP 1 @exists = 1 FROM MyTable WHERE ...
IF @exists = 1
See Also
Migration Issues for Natively Compiled Stored Procedures
Transact-SQL Constructs Not Supported by In-Memory OLTP