$structVariantType = Variant<a: Int32, b: String>;

$optionalData = [
    <|variantValue: Just(Variant(1,       "a", $structVariantType))|>,
    <|variantValue: Nothing(OptionalType($structVariantType))|>,
    <|variantValue: Just(Variant("world", "b", $structVariantType))|>,
];

SELECT Way(variantValue) AS way FROM as_table($optionalData);