Room

Room relation

//one-to-many relation
@Entity(tableName = "TicketGroup")
data class TicketGroup(
    @PrimaryKey(autoGenerate = false)
    val groupId: Int,
    val groupName: String,
)

@Entity(tableName = "Ticket")
data class Ticket(
    @PrimaryKey(autoGenerate = false)
    val ticketId: Int,
    val ticketGroupId: Int,
    val ticketIssue: String,
    val ticketName: String,
    val ticketPrice: Long
)

data class TicketGroupWithTickets(
    @Embedded val ticketGroup: TicketGroup,
    @Relation(
        parentColumn = "groupId",
        entityColumn = "ticketGroupId"
    )
    val ticketList : List<Ticket>
)

@Transaction
@Query("SELECT * FROM TicketGroup")
suspend fun getTicketGroupWithTickets(): List<TicketGroupWithTickets>