OtterMind/Chat2DB · error · IllegalArgumentException

Invalid MongoDB {what}: {name}

Error message

Invalid MongoDB {what}: {name}

What it means

Thrown by the private requireNonEmptyName helper, used by collectionAccessor('collection name') and quoteFieldName('field name'). It rejects null, empty strings, and any name containing a NUL byte (\0). Unlike requireDatabaseName it allows most characters because collection/field names are JSON-quoted and escaped; it only guards against the degenerate cases that cannot be safely interpolated.

Source

Thrown at chat2db-community-server/chat2db-community-plugins/chat2db-community-mongodb/src/main/java/ai/chat2db/plugin/mongodb/MongodbSqlGuards.java:96

                        appendUnicodeEscape(sb, c);
                    } else {
                        sb.append(c);
                    }
            }
        }
        return sb.toString();
    }

    /**
     * Escapes and surrounds one JSON/JavaScript string literal.
     */
    public static String quoteJsonString(String value) {
        return value == null ? "\"null\"" : "\"" + escapeJsonString(value) + "\"";
    }

    private static void requireNonEmptyName(String name, String what) {
        if (name == null || name.isEmpty() || name.indexOf('\0') >= 0) {
            throw new IllegalArgumentException("Invalid MongoDB " + what + ": " + name);
        }
    }

    private static void appendUnicodeEscape(StringBuilder builder, char value) {
        final char[] hex = "0123456789abcdef".toCharArray();
        builder.append("\\u")
                .append(hex[(value >>> 12) & 0xf])
                .append(hex[(value >>> 8) & 0xf])
                .append(hex[(value >>> 4) & 0xf])
                .append(hex[value & 0xf]);
    }
}

View on GitHub (pinned to 5ee1e990e7)

Solutions

1. Null-check collection/field names before invoking the guard and skip or skip-with-default those entries.
2. Filter out or reject empty/blank names at the request-parsing boundary.
3. Sanitize binary-derived names by stripping or rejecting NUL bytes before formatting shell text.
4. Log the originating query when the error occurs to find which metadata row produced the bad name.

Example fix

// before
String accessor = MongodbSqlGuards.collectionAccessor(meta.getName());

// after
String name = meta.getName();
if (name == null || name.isEmpty() || name.indexOf('\0') >= 0) {
    continue; // skip invalid metadata rows
}
String accessor = MongodbSqlGuards.collectionAccessor(name);

if (name == null || name.isEmpty() || name.indexOf('\0') >= 0) {
    return; // skip invalid metadata rows
}
MongodbSqlGuards.collectionAccessor(name);

static boolean isValidMongoName(String name) {
    return name != null && !name.isEmpty() && name.indexOf('\0') < 0;
}

try {
    MongodbSqlGuards.quoteFieldName(name);
} catch (IllegalArgumentException e) {
    log.warn("Skipping field with invalid name");
}

When it happens

Trigger: Calling MongodbSqlGuards.collectionAccessor(name) or quoteFieldName(name) with a null argument, an empty string, or a string that contains a NUL character (often a sign of truncated/corrupted C-string data or a malformed request payload).

Common situations: A metadata fetch returns null for a collection name (e.g. a system namespace that has no friendly name); a field name comes from a user-built JSON where a key was left blank; binary data containing NUL bytes leaks into a name field.

Related errors

• Unsafe column type name from metadata: {typeName}
• Unsafe H2 column default from metadata: {columnDefault}
• Missing JDBC type for Kylin column: {name}
• Unsupported Kylin JDBC column type: {jdbcType}
• Missing JDBC type name for Kylin ARRAY column: {name}

AI-assisted analysis of OtterMind/Chat2DB@5ee1e990e7 (2026-08-14). Data as JSON: /api/errors/ee8acb424b41ade6. Report an issue: GitHub.