Micronaut data-jpa - 一对多 - 子实体没有父引用

Question

我正在使用micronaut-data-hibernate-jpa，并且我有一对多的Parent-Children关系。我试图通过在父存储库上保存操作来保存带有子列表的父实体。父级和子级被保存，但子级没有父级id保存在数据库中。

My Entities定义如下:

import java.util.*
import javax.persistence.*
@Entity
data class Parent(
@Id
@GeneratedValue
var id: UUID? = null,
var name: String,
@OneToMany(mappedBy = "parent",cascade = [CascadeType.ALL])
var children: List<Child> = listOf(),
)

@Entity
data class Child(
@Id
@GeneratedValue
var id: UUID? = null,
var name: String = "",
@ManyToOne(fetch = FetchType.EAGER, cascade = [CascadeType.ALL])
var parent: Parent? = null,
)

使用CrudRepository创建存储库

import io.micronaut.data.annotation.Repository
import io.micronaut.data.repository.CrudRepository
import java.util.*
@Repository
interface ParentRepository : CrudRepository<Parent, UUID>
@Repository
interface ChildRepository : CrudRepository<Child, UUID>

我正在使用简单的测试来检查我的设置是否正常，但显然有问题

import io.micronaut.test.extensions.junit5.annotation.MicronautTest
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.Assertions.assertEquals
import org.junit.jupiter.api.Assertions.assertNotNull
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
@MicronautTest
class OneToManyTest(
private val parentRepository: ParentRepository,
private val childRepository: ChildRepository,
) {
@BeforeEach
fun setUp() {
val childA = Child(name = "Child A")
val childB = Child(name = "Child B")
val parentOne = Parent(name = "Parent 1", children = listOf(childA, childB))
parentRepository.save(parentOne)
val parentTwo = Parent(name = "Parent 2")
val childC = Child(name = "Child C", parent = parentTwo)
childRepository.save(childC)
}
@AfterEach
fun clean() {
childRepository.deleteAll()
parentRepository.deleteAll()
}
@Test //THIS TEST FAILS
fun `Parent should have child when saved by parent`() {
val actual = parentRepository.findAll().toList().filter { it.name == "Parent 1" }[0]
assertEquals(2, actual.children.size)
}
@Test //THIS TEST FAILS
fun `Child should have parent when saved by parent`() {
val actual = childRepository.findAll().toList().filter { it.name != "Child C" }
assertEquals(2, actual.size)  // THIS ASSERT IS OK
assertNotNull(actual[0].parent)
assertNotNull(actual[1].parent)
}
@Test //THIS TEST IS FINE
fun `Parent should have child when saved by child`() {
val actual = parentRepository.findAll().toList().filter { it.name == "Parent 2" }[0]
assertEquals(1, actual.children.size)
}
@Test //THIS TEST IS FINE
fun `Child should have parent when saved by child`() {
val actual = childRepository.findAll().toList().filter { it.name == "Child C" }[0]
assertNotNull(actual.parent)
}
}

我不知道这是否相关，但我使用Flyway生成表，我使用postgres

迁移脚本:

CREATE
EXTENSION IF NOT EXISTS "uuid-ossp";
CREATE TABLE parent
(
id   UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
name CHARACTER VARYING NOT NULL
);
CREATE TABLE child
(
id        UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
name      CHARACTER VARYING NOT NULL,
parent_id UUID REFERENCES parent (id)
)

Answer 1

你声明了mappedBy，它定义了谁是关系的所有者，在你的例子中它是Child，所以你应该在那里分配parent。