ManyToOne with embedded Id

[Distractic]

Hello !

I have these classes :

@KomapperEntity
@KomapperTable("guild")
@KomapperOneToMany(GuildMemberDef::class, "members")
public data class Guild(
    @KomapperId
    @KomapperAutoIncrement
    val id: Int,
    val name: String,
    val owner: UUID,
    @KomapperCreatedAt
    val createdAt: Instant,
)

public data class GuildMemberDefId(
    public val guildId: Int,
    public val memberId: UUID,
)

public enum class GuildMemberState {
    MEMBER,
    PENDING,
}

@KomapperEntity
@KomapperTable("guild_member")
@KomapperManyToOne(Guild::class, "guild", KomapperLink("id.guildId", "id"))
public data class GuildMemberDef(
    @KomapperEmbeddedId
    val id: GuildMemberDefId,
    @KomapperEnum(EnumType.NAME)
    val state: GuildMemberState,
    @KomapperCreatedAt
    val createdAt: Instant,
)

However, for the KomapperLink, I have an error :

> Task :kspKotlin FAILED
e: [ksp] @KomapperLink.source "GuildMemberDef.guildId" is invalid. It must be one of [guildMemberDef].
e: Error occurred in KSP, check log for detail

How can I use the guildId in id into KomapperLink ?

[nakamura-to]

Hi,

You do not need to use KomapperLink in your case.
KomapperLink is used to identify a single name from multiple names specified in the KomapperEntity's aliases property.

[Distractic]

Thanks for your response!

So how Komapper knows on which field the id (of Guild) should be mapped ?

[nakamura-to]

It depends on the JOIN clause in your query.
Perhaps you need the following query:

val g = Meta.guild
val m = Meta.guildMemberDef
val query = QueryDsl.from(g).innerJoin(m) { g.id eq m.id.guildId }.includeAll()