How to use Postgresql enum type via Kotlin Exposed ORM?

Question

I have added some Postgresql types to Exposed as extensions. It has two ready types named enumeration and enumerationByName. I tested both of them with no success for mapping a postgre enum type to Kotlin enum class. In both reading and writing it raises error

enum class TicketStatus(val status: String) {
    Open("open"),
    Close("close"),
    InProgress("in_progress")
}

class Ticket(id: EntityID<UUID>) : Entity<UUID>(id) {
    companion object : EntityClass<UUID, Ticket>(Tickets)

    var geom by Tickets.geom
    var description by Tickets.description
    var status by Tickets.status
    var createdAt by Tickets.createdAt
    var updatedAt by Tickets.updatedAt
    var owner by Tickets.owner
}

When reading:

java.lang.IllegalStateException: open is not valid for enum TicketStatus

Answer 1

You should declare status column as follow:

object Tickets: Table() {
   val status = enumeration("status", TicketStatus::class.java) // will create integer column
   val status = enumerationByName("status", TicketStatus::class.java) // will create varchar with TicketStatus names
}

Answer 2

I realize this is an old question, but if anyone is still looking for an answer here you go:

Exposed has a customEnumeration that can be used to deal with Enums, and is particularly useful if you are using Strings, or another non-default enumerator to back your enum.

For postgres, you'll first need to define a class like so:

class PGEnum<T:Enum<T>>(enumTypeName: String, enumValue: T?) : PGobject() {
    init {
        value = enumValue?.name
        type = enumTypeName
    }
}

Then in your table definition, use the following to define your column, replacing the placeholders as necessary:

val enumColumn = customEnumeration(
            "ENUM_COLUMN",
            "ENUM_SCHEMA.ENUM_TYPE",
            { value ->
                when (value) {
                    is PGobject -> LocalEnumClass.valueOf(value.value)
                    is String -> LocalEnumClass.valueOf(value)
                    else -> error("Can't convert ENUM_COLUMN")
                }
            },
            { PGEnum("ENUM_SCHEMA.ENUM_TYPE", it) }
)

I was running into the same org.postgresql.util.PGobject is not valid for enum before I did this.

See here for more information, and for non-Postgres databases