FOR UPDATE has been incorrectly specified for a READ ONLY cursor

Error constant SQLE_NON_UPDATEABLE_CURSOR
ODBC 2 State 42000
ODBC 3 State 42000
Severity 15
SQLCODE –813
SQLSTATE 42W36
Sybase error code 7301
Probable cause

You attempted to declare a cursor FOR UPDATE on a query that is not updatable. Queries that contain DISTINCT, GROUP BY, HAVING, INTERSECT, EXCEPT, or UNION, or that contain aggregate functions are read-only. If the ansi_update_constraints option is on, then queries that contain a join are read-only. If the query references a view then the view may be non-updatable.