Supported syntax for outer joins differs between Adaptive Server, SQL Anywhere, and SAP Sybase IQ.
Adaptive Server fully supports *= and =* Transact-SQL syntax for outer joins.
SQL Anywhere and SAP Sybase IQ support Transact-SQL outer joins, but reject some complex Transact-SQL outer joins that are potentially ambiguous.
SAP Sybase IQ does not support chained (nested) Transact-SQL outer joins. Use ANSI syntax for this type of multiple outer join.
For detailed information on Transact-SQL outer joins, including ANSI syntax alternatives, see the white paper Semantics and Compatibility of Transact-SQL Outer Joins, on the SAP Community Network. Although written for SQL Anywhere, the information in the document also applies to SAP Sybase IQ.