Ebean not persisting foreign keys - scala

Question

I have a simple Entity class like;
case class Place(var name: String) extends Model with GeoLocPoint with HasGeoLoc with ContainsTime with HasId {
var number: String = _ // Building number on the street.
var placeGroupId: Long = _
var chainId: Long = _
#OneToOne
#JoinColumn(name = "logo_id")
var logo: Image = _
#OneToOne
#JoinColumn(name = "cover_id")
var cover: Image = _
...
}
And the image class is;
package models.images
import javax.persistence.Entity
import models.HasId
import models.places.placegroups.places.{Place, LinkedToPlace}
import play.api.libs.json._
import play.db.ebean.Model
import play.db.ebean.Model.Finder
/**
* Created by asheshambasta on 31/12/14.
*/
#Entity
case class Image(
filePath: String,
src: String,
format: String,
role: String // C: cover, L: logo, G: gallery
) extends Model with HasId with LinkedToPlace {
var caption: String = _
}
Now when a place is created, I'm attaching a default image to it;
newPlace.save
val imgDir = Play.current.configuration.getString("static.dir").getOrElse("/tmp")
val imgUrl = Play.current.configuration.getString("static.url.img").getOrElse("/static/img")
val imgType = Play.current.configuration.getString("img.default.type").getOrElse("image/jpeg")
val coverFile = Play.current.configuration.getString("img.default.cover.file").getOrElse("default-cover.jpg")
val logoFile = Play.current.configuration.getString("img.default.cover.file").getOrElse("default-cover.jpg")
val cover = new Image(imgDir + "/" + coverFile, imgUrl + "/" + coverFile, imgType, "C")
cover.place = newPlace
cover.save
val logo = new Image(imgDir + "/" + logoFile, imgUrl + "/" + logoFile, imgType, "L")
logo.place = newPlace
logo.save
newPlace.cover = cover
newPlace.logo = logo
newPlace.update
But then every time, I see that the images get persisted correctly with the right place_id but the place logo and the cover don't. They stay null.
This seems straight forward, and yet it doesn't work. Does anyone have any pointers to why?

Answer 1

There are some innacuracies in provided code. There is
logo.place = newPlace
but there is no place field in Image class.
There is also place_id column mentioned but I cannot see it in the code. But there are logo_id and cover_id columns. When you do one-to-one relation you should add join-column only on one side of this relation. So it should be only logo_id and cover_id columns on Place table. Adding only place_id column on Image table would not work because there would be two rows in Image table with the same place_id and this would be impossible to distinguish which should be mapped to logo field and which to cover field.
I made some corrections and simplifications to make this code compile and work.
Place.scala:
#Entity
class Place( var aId: Int, var aNumber: String) extends Model{
#Id
val id:Int=aId
#Column(name="number")
var number: String = aNumber
#OneToOne
#JoinColumn (name = "logo_id")
var logo: Image = _
#OneToOne
#JoinColumn(name = "cover_id")
var cover: Image = _
}
Image.class:
#Entity
#Table(name = "image")
class Image(var aId: Int, var aCaption: String) extends Model {
#Id
val id:Int=aId
#Column(name="caption")
var caption: String = aCaption
}
test method:
"EbeanTest" should {
"placeTest" in new WithApplication {
val newPlace = new Place(1, "aaa")
newPlace.save
val logo: Image = new Image(1, "111");
logo.save
val cover: Image = new Image(2, "222");
cover.save
newPlace.logo=logo
newPlace.cover=cover
newPlace.update
val cList = Ebean.find(classOf[Place]).findList()
for (
element <- cList
) println(element.id+" "+element.number+" "+element.logo.id+" "+element.cover.id)
}
}