Adaptive Server Enterprise has Transact-SQL extensions that
permit predicates to compare the Null value. For example, {col} = Null means {col} Is
Null.
Adaptive Server Anywhere and IQ use ANSI semantics for Null comparisons unless the ANSINULL option is set to OFF in which case such comparisons are Adaptive Server Enterprise-compatible.
Adaptive Server Anywhere 8.0 adds support for the TDS_EMPTY_STRING_AS_NULL
to offer Adaptive Server Enterprise compatibility in mapping empty
strings to the Null value.
