Function json_to_variant 

pub fn json_to_variant(
    child: Expression,
    shredding: ShreddingSpec,
) -> Expression

Creates a JsonToVariant expression that parses child’s JSON strings into Variant values, shredding the paths selected by shredding.

child must produce Json extension values; the result is Variant with the input’s nullability. Rows containing invalid JSON fail the expression.

Note that this is a lossy, normalizing conversion. See JsonToVariant for the full list of caveats.