SQL: What is ANSI NULLS? Posted on February 23, 2021 By rich No Comments on SQL: What is ANSI NULLS? In SQL by default ANSI NULLS is switched ON and this means that “NULL does not equal NULL”. To prove this we can write some code.SET ANSI_NULLS ONGOIF NULL = NULL PRINT ‘yess… null=null’ELSE PRINT ‘no… null<>null’