Function json_not_exists 

pub fn json_not_exists<'a, L>(
    left: L,
    path: &'a str,
) -> SQL<'a, SQLiteValue<'a>>
where
    L: ToSQL<'a, SQLiteValue<'a>>,

Builds json_type(left, path) IS NULL: the JSON document has no value at path.

Examples

let column = SQL::<SQLiteValue>::raw("metadata");
let condition = json_not_exists(column, "$.theme");
assert_eq!(condition.sql(), "json_type( metadata , ? ) IS NULL");