Informix Error -591

Reasons / Common Causes

-591 fires when a DEFAULT clause's value doesn't match the column's (or SPL variable's) type, or is too long for it — a general type/length mismatch, distinct from the more specific DEFAULT restrictions covered by -592/-593/-594.

1. A DEFAULT value of the wrong type for the column/variable — a string default for a numeric column, or vice versa.
2. A DEFAULT string value too long for the column's declared length (CHAR(n)/VARCHAR(n)).
3. A DEFAULT value that doesn't parse as a valid literal of the declared type — an improperly formatted date/datetime default, for example.

Solutions / Resolution

1. Confirm the DEFAULT value's type and length match the column's (or variable's) declared type, per the official guidance.
2. For a table column, use the DEFAULT clause within CREATE TABLE with a value matching the column's type:

   CREATE TABLE orders (order_id INT, status CHAR(10) DEFAULT 'pending');
   

3. For an SPL routine variable, use the DEFAULT clause within a DEFINE statement, per the official guidance, with a matching value:

   DEFINE v_status CHAR(10) DEFAULT 'pending';
   

Examples

A too-long default

CREATE TABLE orders (order_id INT, status CHAR(5) DEFAULT 'pending');
-- -591: 'pending' (7 chars) exceeds CHAR(5)

Corrected

CREATE TABLE orders (order_id INT, status CHAR(10) DEFAULT 'pending');

Diagnostic Checks

1. Compare the DEFAULT value's type and length against the column's/variable's declared type before running the statement.

Related Errors / Related Topics

• -592 — "Cannot specify column to be not null when the default value is null." A related but more specific DEFAULT-clause restriction, about a NULL default conflicting with NOT NULL.
• -593 — "Cannot specify default value for SERIAL or SERIAL8 or BIGSERIAL column." A related restriction: DEFAULT isn't meaningful on an auto-generated serial column at all.
• -594 — "Cannot specify non-null default value for TEXT or BYTE column." A related restriction: only NULL is a valid default for TEXT/BYTE columns.

A general type/length mismatch in a DEFAULT clause — check the value against the column's or variable's declared type first.