Adaptive Server Enterprise has Transact-SQL extensions that
permit predicates to compare the null value. For example, {col} = Null means {col} Is
Null.
SQL Anywhere and Sybase 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.
SQL Anywhere 8.0 and later adds support for the TDS_EMPTY_STRING_AS_NULL to
offer Adaptive Server Enterprise compatibility in mapping empty
strings to the null value.
