$tupleVariantType = Variant<Int32, String>;

$data = [
    <|intValue: 1,  strValue: "0"|>,
    <|intValue: 42, strValue: "1"|>,
    <|intValue: 7,  strValue: "hello"|>,
    <|intValue: 99, strValue: "world"|>,
];

SELECT
    Variant(intValue, "0", $tupleVariantType) AS intAlternative,
    Variant(strValue, "1", $tupleVariantType) AS strAlternative
FROM as_table($data);