t8y2/dbx · error

failed to parse constraint %s referenced columns: %w

Error message

failed to parse constraint %s referenced columns: %w

What it means

The referenced-columns attribute of a constraint (e.g. a foreign key's refcolumns) could not be parsed into numeric column identifiers. The error names the constraint so the offending catalog row can be located.

Source

Thrown at agents/drivers/kingbase-go/kingbase_metadata.go:1878

		deferrable, initiallyDeferred bool
		valid, enabled                bool
	}
	raw := []rawConstraint{}
	for rows.Next() {
		var item rawConstraint
		var columnsRaw, refColumnsRaw, validRaw, statusRaw any
		if err := rows.Scan(&item.name, &item.kind, &item.definition, &columnsRaw, &item.refSchema, &item.refTable, &refColumnsRaw, &item.matchType, &item.onUpdate, &item.onDelete, &item.deferrable, &item.initiallyDeferred, &validRaw, &statusRaw); err != nil {
			return nil, err
		}
		item.valid = parseConstraintEnabled(validRaw)
		item.enabled = parseConstraintEnabled(statusRaw)
		item.columns, err = parseCatalogAttributeNumbers(columnsRaw)
		if err != nil {
			return nil, fmt.Errorf("failed to parse constraint %s columns: %w", item.name, err)
		}
		item.refColumns, err = parseCatalogAttributeNumbers(refColumnsRaw)
		if err != nil {
			return nil, fmt.Errorf("failed to parse constraint %s referenced columns: %w", item.name, err)
		}
		raw = append(raw, item)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}

	attributes, err := s.relationAttributesByNumber(catalog, prefix, effective, table)
	if err != nil {
		return nil, err
	}
	refAttributes := map[string]map[int]string{}
	result := make([]constraintInfo, 0, len(raw))
	for _, item := range raw {
		constraint := constraintInfo{
			Name: item.name, ConstraintType: kingbaseConstraintTypeName(item.kind), Definition: item.definition,
			Columns: []string{}, RefColumns: []string{}, Deferrable: item.deferrable,
			// FK details are retained for API completeness and future unified

View on GitHub (pinned to c0390bff16)

Solutions

1. Read the wrapped error to identify the malformed refcolumns value
2. Query the raw refcolumns attribute for the named constraint to inspect the format
3. Confirm driver and Kingbase server versions are compatible
4. Fix or drop/recreate the malformed foreign key constraint
5. Patch parseCatalogAttributeNumbers to tolerate the server's format

Example fix

// before
refCols, err := parseCatalogAttributeNumbers(refColumnsRaw)
// after: skip/warn on non-numeric payloads instead of failing the whole listing
refCols, perr := parseCatalogAttributeNumbers(refColumnsRaw)
if perr != nil {
    log.Warnf("constraint %s refcolumns unparsable, skipping", item.name)
    refCols = nil
}

// Go: verify FK refcolumns attribute is parseable before listing
var refCols sql.NullString
err := db.QueryRow(`SELECT confkey FROM pg_constraint WHERE conname=$1 AND contype='f'`, name).Scan(&refCols)
if err != nil || !refCols.Valid || refCols.String == "" {
    return fmt.Errorf("FK %s refcolumns attribute missing", name)
}

conns, err := server.GetTableConstraints(ctx, schema, table)
if err != nil {
    if strings.Contains(err.Error(), "referenced columns") {
        return fallbackRawConstraints(db, schema, table)
    }
    return err
}

When it happens

Trigger: Listing constraints for a table whose foreign-key rows have a NULL/malformed refcolumns attribute, e.g. when a FK references a partitioned or dropped relation or the catalog stores an unexpected delimiter format.

Common situations: Kingbase version mismatches in FK catalog format; FKs pointing at tables in schemas the introspection query cannot resolve; corrupted system catalogs after failed migrations.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse constraint %s columns: %w
• list custom types in schema %q: %w
• failed to parse foreign key %s columns: %w
• failed to parse foreign key %s referenced columns: %w
• trigger %q is ambiguous in schema %q; relation_name is requi

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/cbda1317912d1d72. Report an issue: GitHub.