Sybase Adaptive Server Anywhere Reference page 810

Alphabetic list of error messages
FOR UPDATE has been incorrectly specified for a READ ONLY
cursor.
Probable cause
Foreign key '%1' for table '%2' duplicates an existing foreign key
Probable cause
792
Item Value
SQLCODE -813
Constant SQLE_NON_UPDATEABLE_CURSOR
SQLSTATE 42W36
Sybase error code 7301
ODBC 2 State 42000
ODBC 3 State 42000
You attempted to declare a cursor FOR UPDATE on a query that is not
updatable. Queries that contain DISTINCT, GROUP BY, HAVING, or
UNION, or that contain aggregate functions are read only. If the
ANSI_UPDATE_CONSTRAINTS option is on, then queries that contain an
join are read only. If the query references a view then the view may be non-
updatable.
Item Value
SQLCODE -251
Constant SQLE_DUPLICATE_FOREIGN_KEY
SQLSTATE 52W06
Sybase error code 1909
ODBC 2 State 42000
ODBC 3 State 42000
Parameter 1 The role name of the new foreign key.
Parameter 2 The table containing the foreign key.
You attempted to define a foreign key that already exists.