Error using optReference with refColumn

[fracaron]

I have tried to use optReference() for a nullable foreign key on Table but I get the following error:

Type parameter bound for T in fun <T : Comparable<T?>> optReference(name: String, refColumn: Column<T>, onDelete: ReferenceOption? = ..., onUpdate: ReferenceOption? = ...): Column<T?>
 is not satisfied: inferred type Int is not a subtype of Comparable<Int?>

As a workaround, I am using reference with nullable().

[Tapac]

Could you provide a sample mapping which fails?

[fracaron]

This is failling on optReference on RoleTable:

object ModuleTable: Table(name = "module") {
    val id = integer("id").autoIncrement().primaryKey()
    val name = varchar(name = "name", length = 125).uniqueIndex()
    val description = varchar("description", 125)
}

object RoleTable: Table(name = "role") {
    val id = integer("id").autoIncrement().primaryKey()
    val name = varchar("name", 125)
    val moduleId = optReference(
        name = "module_id",
        refColumn = ModuleTable.id,
        onDelete = ReferenceOption.CASCADE
    )

For now as a workaround, I can use something like:

object RoleTable: Table(name = "role") {
    val id = integer("id").autoIncrement().primaryKey().uniqueIndex()
    val name = varchar("name", 125)
    val description = varchar("description", 125)
    val moduleId = reference(
        name = "module_id",
        refColumn = ModuleTable.id,
        onDelete = ReferenceOption.CASCADE
    ).nullable()