r2dbc: insert() operation does not work properly when the id is wrapped in a data class

[GeorgePap-719]

Hi, i have encountered a problem. I have a simple entity and im saving this entity in db with r2dbc using R2dbcEntityTemplate directly :

class MessageRepositoryImpl(private val template: R2dbcEntityTemplate) : MessageRepository {
    override suspend fun save(messageEntity: MessageEntity): MessageEntity =
        template.insert<MessageEntity>().usingAndAwait(messageEntity)
}

So far so good.
now i want to refactor my entity's id to be a data class. for example:
before:

@Table("messages")
data class MessageEntity(
    @Id
    @Column("id")
    val id: Int = 0,
}

after:

data class MessageId(private val value: Int) {
    fun toInt() = value
    override fun toString(): String = value.toString()
}

@Table("messages")
data class MessageEntity(
    @Id
    @Column("id")
    val id: MessageId = MessageId(0)
}

Now whenever i save something with above save() function it does not return the write result like before (i.e. the id which is on purpose 0 does not get returned with the actual value). But the entity is saved properly in db with proper (auto-increased) id, meaning if i search for it the result is correct.

Additional info

Note: i have custom @WritingConverter & @ReadingConverter for this entity:

@Component
@WritingConverter
class MessageToRowConverter : Converter<MessageEntity, OutboundRow> {
    override fun convert(source: MessageEntity): OutboundRow {
        return OutboundRow()
            .append("id", source.id.toInt())
    }
}

@Component
@ReadingConverter
class RowToMessageConverter : Converter<Row, MessageEntity> {
    override fun convert(source: Row): MessageEntity {
        println("converting from row")
        return MessageEntity(
            id = MessageId(source.getColumn("id"))
        )
    }
}

Note 2:
I searched through other issues and i found spring-projects/spring-data-r2dbc#49 and #218. I think my case is different from them since my entity is actual saved in db properly and with proper id.

[mp911de]

Composite Identifiers (that is what this boils down to) are not yet supported.

[GeorgePap-719]

Thank you for the answer. I'm not familiar with composite identifiers, is there any issue/link/doc for this (i searched the issues and could not find one)?

[mp911de]

You can follow #1276 for the composite primary key feature. Wrapping the primary key value in a different type creates a composite key type because the identifier type no longer matches a supported primitive type.

[mp911de]

Closing as a duplicate for the time being.