having a class such as (this is kotlin, but the code is very understandable):
#Repository
interface ScoresRepository : MongoRepository<Score, String> {
fun countAllByScoreIsBetween(min: Int, max: Int): Int
}
#Document
data class Score(
#Id var score: Int,
)
Is the between inclusive or exclusive? That is, if I have scores 1-10, and I called:
countAllByScoreIsBetween(3,6) would I get 4 or 2? or maybe something else - bottom is inclusive and top is exclusive?
Tests (with testcontainers) show this:
#Autowired
lateinit var scoresRepository: ScoresRepository
#Test
fun test() {
for (i in 1..10) {
scoresRepository.save(Score(score = i))
}
val count = scoresRepository.countAllByScoreIsBetween(3, 6)
assertThat(count).isEqualTo(2)
}
So as far as I see, both params are not included. That is, Between means everything between the values, not including the values themselves.
Related
I'm developing a Spring Boot application with Spring Data JPA. I'm using a custom JPQL query to group by some field and get the count. Following is my repository method.
#Query("SELECT v.status.name, count(v) as cnt FROM Pet v GROUP BY v.status.name")
List<Object[]> countByStatus();
It's working and result is obtained as follows:
[
[
"pending",
1
],
[
"available",
4
]
]
However, I would like my Rest endpoint to respond with an output which is formatted like this
{
"pending": 1,
"available": 4
}
How can I achieve this?
Basically you want to produce a JSON where its properties ("pending", "available") are dynamic and come from the SELECT v.status.name part of the query.
Create a DTO to hold the row values:
package com.example.demo;
public class ResultDTO {
private final String key;
private final Long value;
public ResultDTO(String key, Long value) {
this.key = key;
this.value = value;
}
public String getKey() {
return key;
}
public Long getValue() {
return value;
}
}
Change your query to create a new ResultDTO per row:
#Query("SELECT new com.example.demo.ResultDTO(v.status.name, count(v)) as cnt FROM Pet v GROUP BY v.status.name")
List<ResultDTO> countByStatus();
"com.example.demo" is my package, you should change it to yours.
Then from your service class or from your controller you have to convert the List<ResultDTO> to a Map<String, Long> holding all rows' keys and values.
final List<ResultDTO> repositoryResults = yourRepository.countByStatus();
final Map<String, Long> results = repositoryResults.stream().collect(Collectors.toMap(ResultDTO::getKey, ResultDTO::getValue));
Your controller should be able to transform final Map<String, Long> results to the desired JSON
I have two collections called persons and addresses. The idea is to have person hold an address in the field address. I use Spring Data MongoDB to persist those mentioned documents.
My usual way of crafting the "relation" between Person > Address was to store the ID of the address and give it to the person object. Later when I find() a person I resolve the address object by it's id and voila I have my person + address.
However I find this somewhat every cumbersome since in my code I just want to add the Address object as whole and not only it's ID so I can work with it while also saving it to the repository at any point of time.
I therefore started a little unit test to see how Spring Data MongoDB saves the Address object if it's just a field of Person and is not saved by it's own Repository.
This is what I came up with:
import org.springframework.data.mongodb.core.mapping.Document
import org.springframework.data.mongodb.repository.MongoRepository
import org.springframework.stereotype.Repository
#Document("person")
data class Person(
val id: String,
val name: String,
val age: Int,
var address: Address
)
#Document("addresses")
data class Address(
val id: String,
val street: String?,
val number: Int?
)
#Repository
interface PersonRepository : MongoRepository<Person, String>
#Repository
interface AddressRepository : MongoRepository<Address, String>
And this is the unit test - that fails with the last steps as I was expecting:
internal class FooTest #Autowired constructor(
private val personRepository: PersonRepository,
private val addressRepository: AddressRepository
) {
#Test
fun `some experiment`() {
val testPerson = Person("001", "Peter", 25, Address("011","Lumberbumber", 12))
personRepository.save(testPerson)
val person = personRepository.findAll()[0]
assertThat(person).isNotNull
assertThat(person.address).isNotNull
assertThat(person.address.street).isEqualTo("Lumberbumber")
assertThat(person.address.number).isEqualTo(12)
// works because address was just copied into the object structure
// of `person` and was not seen as a standalone document
val address = addressRepository.findAll()[0]
assertThat(address.street).isEqualTo("Lumberbumber") // fails
assertThat(address.number).isEqualTo(12) // fails
// As expected `address` was not persisted alongside the `person` document.
}
}
So I thought about using AbstractMongoEventListener<Person> to intercept the saving process and pick the Address object out from Person here and do a addressRepository.save(addressDocument) while putting a lightweight address object (only having the ID) back in the Person document.
The same I'd to in the reverse when doing a find for Person and assembling Person and Address together again.
#Component
class MongoSaveInterceptor(
val addressRepository: AddressRepository
) : AbstractMongoEventListener<Person>() {
override fun onBeforeConvert(event: BeforeConvertEvent<Person>) {
val personToSave = event.source
val extractedAddress = personToSave.address
val idOfAddress = addressRepository.save(extractedAddress).id
personToSave.address = Address(idOfAddress, null, null)
}
override fun onAfterConvert(event: AfterConvertEvent<Person>) {
val person = event.source
val idOfAddress = person.address.id
val foundAddress = addressRepository.findById(idOfAddress)
foundAddress.ifPresent {
person.address = it
}
}
}
It works that way and might be a workaround solution for my requirement.
BUT
I feel that there has to be something like that already working and I might just need to find the proper configuration for that.
That's where I am stuck atm and need some guidance.
Another research showed me it's about #DBRef (https://www.baeldung.com/cascading-with-dbref-and-lifecycle-events-in-spring-data-mongodb) I have to use. This way Spring Data MongoDB stores the embedded document class and resolves it when loading the parent document object from the database.
Looking at the sample code from specification-argument-resolver,
#Controller
public class SampleController {
#Autowired
CustomerRepository customerRepository;
#RequestMapping("/find")
public List<Customer> findByRegistrationDate(
#And({
#Spec(path = "name", params = "name", spec = Equal.class),
#Spec(path = "registrationDate", params = "registrationDate", spec = GreaterThanOrEqual.class)
}) Specification<Customer> spec) {
return customerRepository.findAll(spec);
}
}
#Entity
public class Customer {
String name;
Date registrationDate;
}
Looking at the sample code from specification-argument-resolver, the sample request looks like below:
GET /find?name=John®istrationDate=2020-06-19
Is there a way for the query params to reflect the actual operator.
Example: registrationDate>=2020-06-19 instead of just =
I am looking for a hybrid between RSQL and specification-argument-resolver.
You may just use this library: https://github.com/turkraft/spring-filter
It will let you run search queries such as:
/search?filter= average(ratings) > 4.5 and brand.name in ('audi', 'land rover') and (year > 2018 or km < 50000) and color : 'white' and accidents is empty
It supports dates too, and manages very well the n+1 query problem.
I'm new to ROOM library. I've some complex json data structure which i would like to store in ROOM database, i don't know how to use Type convertes for multiple list of objectes. Following are my Entities,
// Trying to put all my custom models in a single table
#Entity(tableName = "myTable")
data class RaceModelDatabase(
#PrimaryKey
val ID: String,
#Embedded val info: CustomModel,
#Embedded(prefix = "parti")
val parti: Map<String,UserModelDatabase> ,
#Embedded val totalTime: Map<String,TimeDataModel>
)
// Custom Models which also has Map objects
data class CustomModel (val name :String, val crdate : String )
data class UserModelDatabase(#Embedded val info : CustomModel,
#Embedded(prefix = "Result_") val result :Map<String,CustomModel>
)
data class TimeDataModel (
val Start : Long,
val End : Long
)
Here is an example of how to use TypeAdapter for one of your Map objects. You could follow the same for the rest.
class RaceTypeConverter {
#JvmStatic
#TypeConverter
fun fromString(value: String): Map<String, TimeDataModel > {
val mapType = object : TypeToken<Map<String, TimeDataModel >>() {}.type
return Gson().fromJson(value, mapType)
}
#TypeConverter
#JvmStatic
fun fromStringMap(map: Map<String, TimeDataModel>): String {
val gson = Gson()
return gson.toJson(map)
}
}
I am looking for a solution to dynamically build queries using Spring Data JPA. I have a GameController which has a RESTful service endpoint /games which takes 4 optional parameters: genre, platform, year, title. The API may be passed none of those, all 4, and every combination in between. If any parameter is not passed it defaults to null. I need a method in the Repository that will build the appropriate query and ideally also still allow Spring Data JPA Paging, although I'm not sure if that is possible.
I found this article but this doesn't seem to be what I need unless I am misunderstanding. http://spring.io/blog/2011/04/26/advanced-spring-data-jpa-specifications-and-querydsl/
I know JPA has a Query Criteria API but really have no idea how to implement this.
I realize I could create a method for each possible scenario but that seems like really bad practice and a lot of unnecessary code.
GameRepository:
package net.jkratz.igdb.repository;
import net.jkratz.igdb.model.Game;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
public interface GameRepository extends JpaRepository<Game, Long> {
#Query("select g from Game g, GamePlatformMap gpm, Platform p where g = gpm.game and gpm.platform = p and p.id = :platform")
Page<Game> getGamesByPlatform(#Param("platform") Long platformId, Pageable pageable);
#Query("select g from Game g where g.title like :title")
Page<Game> getGamesByTitle(#Param("title") String title, Pageable pageable);
#Query("select g from Game g, GameGenreMap ggm, Genre ge where g = ggm.game and ggm.genre = ge and ge.id = :genreId")
Page<Game> getGamesByGenre(#Param("genre") Long genreId, Pageable pageable);
}
I would say that using QueryDSL is one way of doing what you want.
For example I have a repository defined as below:
public interface UserRepository extends PagingAndSortingRepository<User, Long>, QueryDslPredicateExecutor<User> {
public Page<User> findAll(Predicate predicate, Pageable p);
}
I can call this method with any combination of parameters, like below:
public class UserRepositoryTest{
#Autowired
private UserRepository userRepository;
#Test
public void testFindByGender() {
List<User> users = userRepository.findAll(QUser.user.gender.eq(Gender.M));
Assert.assertEquals(4, users.size());
users = userRepository.findAll(QUser.user.gender.eq(Gender.F));
Assert.assertEquals(2, users.size());
}
#Test
public void testFindByCity() {
List<User> users = userRepository.findAll(QUser.user.address.town.eq("Edinburgh"));
Assert.assertEquals(2, users.size());
users = userRepository.findAll(QUser.user.address.town.eq("Stirling"));
Assert.assertEquals(1, users.size());
}
#Test
public void testFindByGenderAndCity() {
List<User> users = userRepository.findAll(QUser.user.address.town.eq("Glasgow").and(QUser.user.gender.eq(Gender.M)));
Assert.assertEquals(2, users.size());
users = userRepository.findAll(QUser.user.address.town.eq("Glasgow").and(QUser.user.gender.eq(Gender.F)));
Assert.assertEquals(1, users.size());
}
}
For those using Kotlin (and Spring Data JPA), we've just open-sourced a Kotlin JPA Specification DSL library which lets you create type-safe dynamic queries for a JPA Repository.
It uses Spring Data's JpaSpecificationExecutor (i.e. JPA criteria queries), but without the need for any boilerplate or generated metamodel.
The readme has more details on how it works internally, but here's the relevant code examples for a quick intro.
import au.com.console.jpaspecificationsdsl.* // 1. Import Kotlin magic
////
// 2. Declare JPA Entities
#Entity
data class TvShow(
#Id
#GeneratedValue
val id: Int = 0,
val name: String = "",
val synopsis: String = "",
val availableOnNetflix: Boolean = false,
val releaseDate: String? = null,
#OneToMany(cascade = arrayOf(javax.persistence.CascadeType.ALL))
val starRatings: Set<StarRating> = emptySet())
#Entity
data class StarRating(
#Id
#GeneratedValue
val id: Int = 0,
val stars: Int = 0)
////
// 3. Declare JPA Repository with JpaSpecificationExecutor
#Repository
interface TvShowRepository : CrudRepository<TvShow, Int>, JpaSpecificationExecutor<TvShow>
////
// 4. Kotlin Properties are now usable to create fluent specifications
#Service
class MyService #Inject constructor(val tvShowRepo: TvShowRepository) {
fun findShowsReleasedIn2010NotOnNetflix(): List<TvShow> {
return tvShowRepo.findAll(TvShow::availableOnNetflix.isFalse() and TvShow::releaseDate.equal("2010"))
}
/* Fall back to spring API with some extra helpers for more complex join queries */
fun findShowsWithComplexQuery(): List<TvShow> {
return tvShowRepo.findAll(where { equal(it.join(TvShow::starRatings).get(StarRating::stars), 2) })
}
}
For more complex and dynamic queries it's good practice to create functions that use the DSL to make queries more readable (as you would for QueryDSL), and to allow for their composition in complex dynamic queries.
fun hasName(name: String?): Specifications<TvShow>? = name?.let {
TvShow::name.equal(it)
}
fun availableOnNetflix(available: Boolean?): Specifications<TvShow>? = available?.let {
TvShow::availableOnNetflix.equal(it)
}
fun hasKeywordIn(keywords: List<String>?): Specifications<TvShow>? = keywords?.let {
or(keywords.map { hasKeyword(it) })
}
fun hasKeyword(keyword: String?): Specifications<TvShow>? = keyword?.let {
TvShow::synopsis.like("%$keyword%")
}
These functions can be combined with and() and or() for complex nested queries:
val shows = tvShowRepo.findAll(
or(
and(
availableOnNetflix(false),
hasKeywordIn(listOf("Jimmy"))
),
and(
availableOnNetflix(true),
or(
hasKeyword("killer"),
hasKeyword("monster")
)
)
)
)
Or they can be combined with a service-layer query DTO and mapping extension function
/**
* A TV show query DTO - typically used at the service layer.
*/
data class TvShowQuery(
val name: String? = null,
val availableOnNetflix: Boolean? = null,
val keywords: List<String> = listOf()
)
/**
* A single TvShowQuery is equivalent to an AND of all supplied criteria.
* Note: any criteria that is null will be ignored (not included in the query).
*/
fun TvShowQuery.toSpecification(): Specifications<TvShow> = and(
hasName(name),
availableOnNetflix(availableOnNetflix),
hasKeywordIn(keywords)
)
for powerful dynamic queries:
val query = TvShowQuery(availableOnNetflix = false, keywords = listOf("Rick", "Jimmy"))
val shows = tvShowRepo.findAll(query.toSpecification())
JpaSpecificationExecutor supports paging, so you can achieve pageable, type-safe, dynamic queries!
I have got a solution for this. I wrote some code to extend the spring-data-jpa .
I call it spring-data-jpa-extra
spring-data-jpa-extra comes to solve three problem:
dynamic native query support like mybatis
return type can be anything
no code, just sql
You can try it : )