Informix Error -9912: Constraints on collection type column not allowed.

Cause and resolution

Constraints on collection type column not allowed.

Constraint expressions are not supported in the definition of a column of a collection type. Remove the constraint clause.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-9912 fires when a collection-type column's definition includes a constraint expression — per the official guidance.

A constraint expression specified for a collection-type column, per the official guidance — the direct, only cause; constraints aren't supported on collection columns.

Solutions / Resolution

Remove the constraint clause, per the official guidance.

Examples

A constraint on a collection column

CREATE TABLE tab (id INT, items LIST(INT NOT NULL) CHECK (CARDINALITY(items) > 0));
-- -9912

Corrected

CREATE TABLE tab (id INT, items LIST(INT NOT NULL));

Diagnostic Checks

Check collection-type column definitions for a CHECK or other constraint clause, and remove it.

Related Errors / Related Topics

-9911 — "Defaults on collection type column not allowed." The same class of collection-column-definition restriction, on defaults rather than constraints.

A collection-type column had a constraint clause, which isn't supported — remove it.