Scala case class equality when reading from Database - scala

Question

I'm having trouble with checking for equality on a case class that I've mapped to an apache tinkerpop graph, but I want to be able to check for equality after I query the graph.
#label("apartment")
case class Apartment(#id id: Option[Int], address: String, zip: Zip, rooms: Rooms, size: Size, price: Price, link: String, active: Boolean = true, created: Date = new Date()) {}
val ApartmentAddress = Key[String]("address")
Await.result(result, Duration.Inf).foreach(apt => {
val dbResult = graph.V.hasLabel[Apartment].has(ApartmentAddress, apt.address).head().toCC[Apartment]
println(dbResult == apt) //always false :(
})
My problem is that when I've created the object it has no id, and the time stamp on it is obviously different. I read that if you add a second parameter list, it is excluded from equals, so I changed it:
#label("apartment")
case class Apartment(address: String, zip: Zip, rooms: Rooms, size: Size, price: Price, link: String, active: Boolean = true)(#id implicit val id: Option[Int] = None, implicit val created: Date = new Date()) {}
val ApartmentAddress = Key[String]("address")
Await.result(result, Duration.Inf).foreach(apt => {
val dbResult = graph.V.hasLabel[Apartment].has(ApartmentAddress, apt.address).head().toCC[Apartment]
println(dbResult == apt) //true! yay! :D
})
I can now check for equality using ==, but the value from the database loses its id, and the "created" value gets reset. And, one other frustrating thing, they always need to be created with extra parenthesis at the end:
Apartment(address, zip, rooms, size, price, link)()
Is there a way to achieve this functionality without overloading equals? Or make the value from the database maintain the original values using this approach?

Answer 1

It seems in your case, you just need it only for one time comparison, so I would not play with equals and just modified value on comparison
case class Apartment(
#id id: Option[Int] = None,
address: String,
zip: Zip,
rooms: Rooms,
size: Size,
price: Price,
link: String,
active: Boolean = true,
created: Date = new Date(0)) {
}
println(dbResult.copy(id = None, created = new Date(0)) == apt) //true! yay! :D
or add extra function to the class
case class Apartment(
#id id: Option[Int] = None,
address: String,
zip: Zip,
rooms: Rooms,
size: Size,
price: Price,
link: String,
active: Boolean = true,
created: Date = new Date(0)) {
def equalsIgnoreIdAndCreated(other: Apartment) = {
this.equals(other.copy(id = id, created = created))
}
}
println(dbResult.equalsIgnoreIdAndCreated(apt))
You can look at good explanation for case classes in
http://www.alessandrolacava.com/blog/scala-case-classes-in-depth/ and reasons why you should not override equals from automatically generated, otherwise just override equals.