If I have en entity A with a oneToOne composition relation to the entity B,
jmix will create
@JmixEntity
@Table(name = "A", indexes = [
Index(name = "IDX_A_B_OWNING_SIDE", columnList = "B_OWNING_SIDE_ID")
])
@Entity
open class A {
@OnDeleteInverse(DeletePolicy.UNLINK)
@JoinColumn(name = "B_OWNING_SIDE_ID")
@Composition
@OneToOne(fetch = FetchType.LAZY)
var bOwningSide: B? = null
…
}
and
@JmixEntity
@Table(name = "B")
@Entity
open class B {
@JmixGeneratedValue
@Column(name = "ID", nullable = false)
@Id
var id: UUID? = null
@Composition
@NotNull
@OneToOne(fetch = FetchType.LAZY, mappedBy = "bOwningSide", optional = false)
var a: A? = null
…
}
First question, since I can get the error “During synchronization a new object was found through a relationship that was not marked cascade PERSIST” if I create all instances but don’t save them in the good order,
why Jmix don’t set the cascade @OneToOne(fetch = FetchType.LAZY, cascade = [CascadeType.ALL]), is-it safe to add it ?
Second question, since the owning side is the only one valid to edit the relation and get it saved in database, why the reverse side is normal code which can create bug if the dev don’t check the owning side in an affection…
Is-it possible to have a behavior with both side equivalent to read or write the relation ?
Maybe like that ?
@JmixEntity
@Table(name = "A", indexes = [
Index(name = "IDX_A_B_OWNING_SIDE", columnList = "B_OWNING_SIDE_ID")
])
@Entity
open class A {
@OnDeleteInverse(DeletePolicy.UNLINK)
@JoinColumn(name = "B_OWNING_SIDE_ID")
@OneToOne(fetch = FetchType.LAZY, cascade = [CascadeType.ALL])
@Composition
var bOwningSide: B? = null
set(value) {
field = value
if (value?.a != this) {
value?.a = this
}
}
…
}
and
@JmixEntity
@Table(name = "B")
@Entity
open class B {
@JmixGeneratedValue
@Column(name = "ID", nullable = false)
@Id
var id: UUID? = null
@OnDeleteInverse(DeletePolicy.CASCADE)
@OneToOne(fetch = FetchType.LAZY, mappedBy = "bOwningSide", optional = false, cascade = [CascadeType.ALL])
var a: A? = null
set(value) {
field = value
if (value?.bOwningSide != this) {
value?.bOwningSide = this
}
}
…
}