class Person: Object {
    @objc dynamic var name: String = ""
    @objc dynamic var age: Int8 = 0
    @objc dynamic var dog: Dog!
    
    override class func primaryKey() -> String? {
        return "name"
    }
}

class Dog: Object {
    @objc dynamic var name: String = ""
}


let person = Person()
person.name = "Mike"
person.age = 20
person.dog = Dog()
person.dog.name = "Gogo"
    
// 增
RealmBlend.add(obj: person)
    
// 查
let result = RealmBlend.select(type: Person.self, filter: "name='Mike'")
    
if let mike = result.first as? Person {
    print("Mike's age is \(mike.age), and he has a dog name's \(mike.dog.name)")
    
    // 改
    RealmBlend.update {
        mike.dog.name = "Mi"
    }
    
    print("Mike's dog rename to \(mike.dog.name).")
    
    // 删
    RealmBlend.delete(obj: mike)
}
    
let isMikeGone = result.count == 0
    
print(isMikeGone ? "Mike's gone." : "Mike's still there.")