How to compare a UUID with an optional String when using leftJoin

[bitxeno]

   @Table("item")
    struct Item: Codable, Hashable, Identifiable {
        let id: UUID
        var name: String
    }

   @Table("object_relate")
    struct ObjectRelate: Codable, Hashable, Identifiable {
        let id: UUID
        var objectId: String?
        var attribue: String
    }

My actual scheme is more complex than the example. objectId could be Item.id.uuidString, or it could be the string id of a network API object. Now I want to get the ObjectRelate associated with Item, but using the following statement results in an error:

Cannot convert value of type 'CoalesceFunction<TableColumn<ObjectRelate.TableColumns.QueryValue, String?>.QueryValue.Wrapped>' (aka 'CoalesceFunction<TableColumn<ObjectRelate, Optional<String>>.QueryValue.Wrapped>') to expected argument type 'String'

let result = try await database.read { db in
    try Item
        .where({ $0.id == id })
        .leftJoin(ObjectRelate.all) { $0.id == UUID(uuidString: $1.objectId ?? "") }
        .fetchAll(db)
}

I tried the following statement and it doesn't give an error, but I can't get the ObjectRelate data.：

let result = try await database.read { db in
    try Item
        .where({ $0.id == id })
        .leftJoin(ObjectRelate.all) { $0.id == #sql("\($1.objectId)") }
        .fetchAll(db)
}

Is there a way to solve this?