apache/cassandra · error · InvalidRequestException

Unsupported '!=' relation

Error message

Unsupported '!=' relation: %s

What it means

Relation.toRestriction rejects the != operator used with a token() relation: NEQ on token is not supported because it cannot be evaluated against the partitioner's ring during restriction conversion. InvalidRequestException at query preparation.

Solutions

1. Remove the token(...) != value relation.
2. Use token() with equality or range operators, or filter on partition key columns directly if ALLOW FILTERING semantics apply.

When it happens

Trigger: Thrown at src/java/org/apache/cassandra/cql3/Relation.java:199 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/1cba119fd637bf47. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/Relation.java:199

    public boolean onToken()
    {
        return rawExpressions.kind() == ColumnsExpression.Kind.TOKEN;
    }

    /**
     * Converts this <code>Relation</code> into a <code>Restriction</code>.
     *
     * @param table the table metadata
     * @param boundNames the variables specification where to collect the bind variables
     * @return the <code>Restriction</code> corresponding to this <code>Relation</code>
     * @throws InvalidRequestException if this <code>Relation</code> is not valid
     */
    public SingleRestriction toRestriction(TableMetadata table, VariableSpecifications boundNames, Object owner, boolean allowFiltering)
    {
        ColumnsExpression columnsExpression = rawExpressions.prepare(table);

        if (operator == Operator.NEQ && columnsExpression.kind() == ColumnsExpression.Kind.TOKEN)
            throw invalidRequest("Unsupported '!=' relation: %s", this);

        // TODO support restrictions on list elements as we do in conditions, then we can probably move below validations
        //  to ElementExpression prepare/validateColumns
        if (columnsExpression.isMapElementExpression())
        {
            ColumnMetadata column = columnsExpression.firstColumn();
            AbstractType<?> baseType = column.type.unwrap();
            checkFalse(baseType instanceof ListType, "Indexes on list entries (%s[index] = value) are not supported.", column.name);
            checkTrue(baseType instanceof MapType, "Column %s cannot be used as a map", column.name);

            if (column.isClusteringColumn() && baseType.isCollection() && !column.type.isMultiCell())
                throw invalidRequest(FROZEN_MAP_ENTRY_PREDICATES_NOT_SUPPORTED, column.name);

            columnsExpression.collectMarkerSpecification(boundNames, owner);
        }

        operator.validateFor(columnsExpression);

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