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Informix Error -4080: Warning: Operation on NULL returns NULL.

Cause and resolution

Warning: Operation on NULL returns NULL.

While the compiler was optimizing expressions, it found an expression composed of literal values, at least one of which was NULL.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-4080 is a compiler warning: per the official guidance, while optimizing expressions, the compiler found an expression made of literal values where at least one was NULL.

  1. A compile-time expression built from literals, at least one of which is NULL, per the official guidance — the direct cause; the whole expression evaluates to NULL.
Solutions / Resolution
  1. Confirm the NULL literal was intended, since the entire expression resolves to NULL as a result.
Examples
A literal expression involving NULL
CONSTANT x = 5 + NULL
-- -4080: the whole expression is NULL
Diagnostic Checks
  1. Check any compile-time literal expression producing this warning, and confirm NULL was intentionally included.
Related Errors / Related Topics

No closely related error codes are cross-referenced for -4080 in this set yet.

A literal expression includes NULL, so the whole expression evaluates to NULL — confirm this was intended.