Informix Error -2931: There is an error in the format specification.

Reasons / Common Causes

-2931 fires when a FORMAT string in an ATTRIBUTES statement doesn't suit the field's data type — per the official guidance, this includes characters other than # and . for a numeric column, or an incorrect internal length for a DATE column (for example, yyy, which calls for a three-digit year).

1. Invalid characters in a numeric column's FORMAT string (anything besides # and .), per the official guidance — the first named cause.
2. An incorrect internal length in a DATE column's FORMAT string (e.g. a three-digit year), per the official guidance — the second named cause.

Solutions / Resolution

1. Check the content of the FORMAT string against the field's data type, per the official guidance, and correct it.

Examples

An invalid numeric format

ATTRIBUTES
  price = unit_price, FORMAT = "$$$.99";
-- -2931: '$' is not a valid FORMAT character for a numeric column

Corrected

ATTRIBUTES
  price = unit_price, FORMAT = "###.##";

An invalid DATE format length

ATTRIBUTES
  hire_date = hire_date, FORMAT = "mmddyyy";
-- -2931: yyy is a 3-digit year, not a valid DATE length

Corrected

ATTRIBUTES
  hire_date = hire_date, FORMAT = "mmddyyyy";

Diagnostic Checks

1. Check the FORMAT string's characters against the field's data type (#/. only for numeric columns; a valid date-length pattern for DATE columns).

Related Errors / Related Topics

• -2932 — "Formats may be specified only for float, smallfloat, decimal, or date columns." A related FORMAT-clause error, about applying FORMAT to an unsupported data type rather than malforming the format string itself.

The FORMAT string's content doesn't suit its field's data type — correct its characters or length.