OtterMind/Chat2DB · error · IllegalArgumentException

Invalid DB2 index column ordering: {ascOrDesc}

Error message

Invalid DB2 index column ordering: {ascOrDesc}

What it means

Thrown by Db2SqlGuards.requireSortDirection when an index column's sort direction is not ASC or DESC (case-insensitive). The method whitelists only the two legal DB2 index ordering tokens and rejects anything else so a non-escapable value cannot be interpolated into generated CREATE INDEX DDL. This is a fail-closed SQL guard, not a runtime constraint from the DB2 server.

Source

Thrown at chat2db-community-server/chat2db-community-plugins/chat2db-community-db2/src/main/java/ai/chat2db/plugin/db2/Db2SqlGuards.java:102

     * Validates a fallback column type expression (a type name that does not match
     * an enum constant, e.g. {@code VARCHAR(10)}) before it is embedded into
     * generated DDL. Returns the type unchanged when it matches the strict shape;
     * throws otherwise.
     */
    public static String requireColumnTypeExpression(String columnType) {
        if (columnType == null || !FALLBACK_COLUMN_TYPE_PATTERN.matcher(columnType).matches()) {
            throw new IllegalArgumentException("Invalid DB2 column type: " + columnType);
        }
        return columnType;
    }

    /**
     * Validates an index column sort direction against the ASC/DESC whitelist.
     * Returns the direction unchanged when whitelisted; throws otherwise.
     */
    public static String requireSortDirection(String ascOrDesc) {
        if (!"ASC".equalsIgnoreCase(ascOrDesc) && !"DESC".equalsIgnoreCase(ascOrDesc)) {
            throw new IllegalArgumentException("Invalid DB2 index column ordering: " + ascOrDesc);
        }
        return ascOrDesc;
    }
}

View on GitHub (pinned to 5ee1e990e7)

Solutions

1. Normalize ascOrDesc to "ASC"/"DESC" (or blank) before calling the builder so the guard only sees whitelisted tokens.
2. If you control the TableIndexColumn, leave ascOrDesc blank/null instead of passing an invalid sentinel like 'A'.
3. When reading raw DB2 catalog codes, map 'A'->"ASC", 'D'->"DESC" at the metadata layer rather than forwarding them.
4. Wrap the DDL build in try/catch on IllegalArgumentException and report the offending index/column to the user instead of failing the whole build.

Example fix

// before
String dir = indexColumn.getAscOrDesc(); // raw DB2 code 'A' / 'D'
script.append(" ").append(Db2SqlGuards.requireSortDirection(dir));

// after
String dir = indexColumn.getAscOrDesc();
if ("A".equalsIgnoreCase(dir)) dir = "ASC";
else if ("D".equalsIgnoreCase(dir)) dir = "DESC";
if (StringUtils.isNotBlank(dir)) {
    script.append(" ").append(Db2SqlGuards.requireSortDirection(dir));
}

// Run before building DB2 index DDL
static String normalizeDir(String ascOrDesc) {
    if (ascOrDesc == null) return null;
    String t = ascOrDesc.trim();
    if ("A".equalsIgnoreCase(t)) return "ASC";
    if ("D".equalsIgnoreCase(t)) return "DESC";
    if ("ASC".equalsIgnoreCase(t) || "DESC".equalsIgnoreCase(t)) return t.toUpperCase(Locale.ROOT);
    return null; // blank -> skip
}

// Narrow to a known direction before calling the guard
static boolean isDb2SortDir(String v) {
    return v != null && ("ASC".equalsIgnoreCase(v) || "DESC".equalsIgnoreCase(v)
        || "A".equalsIgnoreCase(v) || "D".equalsIgnoreCase(v));
}

When it happens

Trigger: Calling Db2SqlGuards.requireSortDirection(ascOrDesc) with a value that is neither "ASC" nor "DESC" (e.g. null, "", "ASCENDING", "NULLS FIRST", or a metadata-derived corrupted string). Indirectly triggered when DB2 index DDL is built for a TableIndex whose column's getAscOrDesc() returns an unexpected token.

Common situations: Importing DB2 index metadata where the SYSCAT.INDEXCOLUSE sort direction column is blank or null; copying an index model from another dialect that used a non-standard ordering; a tool populating TableIndexColumn.ascOrDesc with the raw DB2 'A'/'D' code instead of the spelled-out direction.

Related errors

• Invalid DM index sort direction: {value}
• Invalid Hive index sort direction: {value}
• Unsupported DM VARCHAR unit: {unit}
• Invalid DM BIT literal: {value}
• DM index must contain at least one named column

AI-assisted analysis of OtterMind/Chat2DB@5ee1e990e7 (2026-08-14). Data as JSON: /api/errors/bfe96b45cfc68dbb. Report an issue: GitHub.