Support default, primitive Kotlin attributes.

[pelletier197]

Default values for fields are not supported for constructor of node entities when querying the database with a custom query.

CREATE (person:Person { id: "first", firstName: "firstName"})
CREATE (person:Person { id: "second"})

with the following data class

@Node("Person")
data class Person(
  val id: String, 
  val firstName: String = "Unknown"
)

and the following repository

interface PersonRepository : Neo4jRepository<Person, String>

calling personRepository.findAll() results in

Could not convert NULL into String; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [null] to type [String] for value 'null';

[michael-simons]

Do you have a reproducer at hand? Cannot reproduce it on 6.0.x nor 6.1.x?

The @Id annotation is missing in your example:

@Node
data class KotlinPersonWithDefaults(
		@Id
		val id: String,
		val firstName: String = "Unknown"
)

Tried

• Kotlin in Java
• Kotlin in Kotlin…
  I'm something missing somewhere.

[pelletier197]

Sorry, my mistake. It actually work with the String, but it doesn't seem to work when the default value is for a primitive. Here is my sample

@Node("TestPerson")
data class TestPersonEntity(
    @Id
    val id: String,
    @Property("name")
    val name: String = "Unknown", // this works
    val otherPrimitive: Int = 32, // <<- this doesn't
)

@Node("TestDepartment")
data class TestDepartmentEntity(
    @Id
    val id: String,
    @Property("name")
    val name: String
)

data class PersonProjection(
    val person: TestPersonEntity,
    val department: TestDepartmentEntity
)

interface TestPersonRepositoryProjection : Neo4jRepository<TestPersonEntity, String> {
    @Query(
        """
        MATCH (person:TestPerson)
        MATCH (person)-[:MEMBER_OF]->(department:TestDepartment)
        return person, department
        """
    )
    fun findPeople(): List<PersonProjection>
}

@Configuration
class TestRepository(
    private val repository: TestPersonRepositoryProjection,
) {
    init {
            println(repository.findPeople())
    }
}

I tested with int and boolean and I get the same error. I assume it's for all primitives, but I haven't tested all of them.

And I executed the following query in Neo4j

CREATE (p1:TestPerson {id: "first", name: "First name"})
CREATE (p2:TestPerson {id: "second"})
CREATE (d:TestDepartment {id: "department", name: "Test"})
CREATE (p1)-[:MEMBER_OF]->(d)
CREATE (p2)-[:MEMBER_OF]->(d)

[michael-simons]

That is helpful. Thank you. Should be able to safely reproduce it. It will probably fail with pure Java, too. Thanks for reporting! Sunny Pelletier ***@***.***> schrieb am Mi. 2. Juni 2021 um 17:53:

…

Sorry, my mistake. It actually work with the String, but it doesn't seem to work when the default value is for a primitive. Here is my sample @node("TestPerson")data class TestPersonEntity( @id val id: String, @Property("name") val name: String = "Unknown", // this works val otherPrimitive: Int = 32, // <<- this doesn't ) @node("TestDepartment")data class TestDepartmentEntity( @id val id: String, @Property("name") val name: String ) data class PersonProjection( val person: TestPersonEntity, val department: TestDepartmentEntity ) interface TestPersonRepositoryProjection : Neo4jRepository<TestPersonEntity, String> { @query( """ MATCH (person:TestPerson) MATCH (person)-[:MEMBER_OF]->(department:TestDepartment) return person, department """ ) fun findPeople(): List<PersonProjection> } @Configurationclass TestRepository( private val repository: TestPersonRepositoryProjection, ) { init { println(repository.findPeople()) } } I tested with int and boolean and I get the same error. I assumed it's for all primitives, but I haven't tested all of them. — You are receiving this because you were assigned. Reply to this email directly, view it on GitHub <#2276 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEAQLY5LPFWJ6HVIBKR3V3TQZHW3ANCNFSM4564CL6A> .