Informix Error -1391: Invalid class specified in AS clause.

Reasons / Common Causes

-1391 fires when the class named in a NEW/COPY operation's AS clause isn't actually derived from the stated (parent) class — per the official guidance, the AS clause's class must be a proper subclass of the class being created/copied.

1. An AS clause naming a class that doesn't inherit from the stated parent class, per the official guidance — the direct, only cause.

Solutions / Resolution

1. Use a class in the AS clause that's genuinely derived from the stated parent class, per the official guidance.
2. Review the class hierarchy if the intended inheritance relationship isn't actually what was designed.

Examples

An AS clause with an unrelated class

DEFINE v_obj Order.Class
LET v_obj = NEW Customer() AS Order.Class
-- -1391: Customer doesn't derive from Order.Class

Corrected

LET v_obj = NEW SpecialOrder() AS Order.Class
-- SpecialOrder genuinely derives from Order.Class

Diagnostic Checks

1. Check the class hierarchy to confirm the AS clause's class actually derives from the stated parent class.

Related Errors / Related Topics

• -1390 — "The class "class" has not been defined in any module in the program." A related class-definition error, about a class missing its definition entirely, rather than an incorrect inheritance relationship.

The AS clause's class doesn't derive from the stated parent class — check the class hierarchy.