Zero-length strings are treated differently in Adaptive Server Enterprise, SAP SQL Anywhere, and SAP Sybase IQ.
Adaptive Server Enterprise treats zero-length strings as the null value.
Adaptive Server Enterprise users store a single space for blank strings.
SAP SQL Anywhere and SAP Sybase IQ follow ANSI semantics for zero-length strings, that is, a zero-length string is a real value; it is not null.