Question

下面您可以找到一个显示我的问题的最小示例：

src/main/kotlin/com/mytest/findallbytest/Application.kt：

package com.mytest.findallbytest

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication

@SpringBootApplication
class MyTestApplication

fun main(args: Array<String>) {
    runApplication<MyTestApplication>(*args)
}

src/main/kotlin/com/mytest/findallbytest/model/Thing.kt：

package com.mytest.findallbytest.model

import org.springframework.data.jpa.domain.AbstractPersistable
import javax.persistence.Entity
import javax.persistence.Table

@Entity
@Table(name = "things")
class Thing(
        val foo: Long,
        val bar: Long
) : AbstractPersistable<Long>()

src/main/kotlin/com/mytest/findallbytest/repository/ThingRepository.kt：

package com.mytest.findallbytest.repository

import com.mytest.findallbytest.model.Thing
import org.springframework.data.jpa.repository.JpaRepository

interface ThingRepository : JpaRepository<Thing, Long> {
    fun findAllByFooAndBar(foos: Iterable<Long>, bars: Iterable<Long>): Iterable<Thing>
}

src/main/resources/application.yml：

spring:
  datasource:
    url: jdbc:h2:mem:db;MODE=PostgreSQL

src/main/resources/db/migration/V1__things.sql：

CREATE SEQUENCE HIBERNATE_SEQUENCE;

CREATE TABLE things (
    id      BIGINT PRIMARY KEY NOT NULL,
    foo     BIGINT NOT NULL,
    bar     BIGINT NOT NULL
);

src/test/kotlin/com/mytest/findallbytest/FullTest.kt：

package com.mytest.findallbytest

import com.mytest.findallbytest.model.Thing
import com.mytest.findallbytest.repository.ThingRepository
import org.assertj.core.api.Assertions.assertThat
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.boot.test.context.SpringBootTest
import org.springframework.test.context.junit.jupiter.SpringExtension

@ExtendWith(SpringExtension::class)
@SpringBootTest
class FullTest {

    @Autowired
    lateinit var repo: ThingRepository

    @Test
    fun `basic entity checks`() {
        repo.save(Thing(1, 2))
        repo.save(Thing(3, 4))
        repo.save(Thing(1, 4))
        assertThat(repo.findAll()).hasSize(3)

        // ERROR: Expected size:<2> but was:<0>
        assertThat(repo.findAllByFooAndBar(listOf(1L, 3L), listOf(2L, 4L))).hasSize(2)
    }
}

问题是findAllByFooAndBar返回一个空列表。但是我希望如此，所以返回三个已保存实体的前两个。

我在做什么错了，如何才能实现我的目标或查询多个字段上匹配的多个实体？

Answer 1

fun findAllByFooInAndBarIn(foos: Iterable<Long>, bars: Iterable<Long>): Iterable<Thing>

Answer 2

一种（不是很好）的解决方案是手动创建查询并使用EntityManager发送查询：

@Repository
class SecondThingRepository(private val entityManager: EntityManager) {
    fun selectByFoosAndBars(foosAndBars: Iterable<Pair<Long, Long>>): Iterable<Thing> {
        val pairsRepr = foosAndBars.joinToString(prefix = "(", postfix = ")") { "(${it.first}, '${it.second}')" }
        val query: TypedQuery<Thing> = entityManager.createQuery("SELECT t FROM Thing t WHERE (t.foo, t.bar) IN $pairsRepr", Thing::class.java)
        return query.resultList
    }
}

然后：

repo2: SecondThingRepository
...
assertThat(repo2.selectByFoosAndBars(listOf(Pair(1L, 2L), Pair(3L, 4L)))).hasSize(2)

如何在JpaRepository中的多个字段中使用FindAllBy？

2 个答案: