In this blog post, you’ll learn more about the Sybase Error Invalid expression in WHERE clause of Transact-SQL outer join and the reason for receiving this error
Sybase SQL Error Message
Invalid expression in WHERE clause of Transact-SQL outer join
Reason for this Error
An expression in the WHERE clause of a query that uses Transact-SQL syntax contains a comparison of a column from the NULL-supplying table with a subquery or an expression that references a column from another table.