@Override
    public Type visitFieldReference(
        FieldReference node, StackableAstVisitorContext<Context> context) {
      ResolvedField field = baseScope.getField(node.getFieldIndex());
      return handleResolvedField(node, field, context);
    }
@return the common supertype between the value type and subquery type
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/analyzer/ExpressionAnalyzer.java