Example of how to use Slick's MappedJdbcType in practice

Example.scala

// This does the conversion from enum to char and vice-versa.
abstract class JDBCCharEnumeration extends Enumeration {
  import slick.jdbc.HsqldbProfile.api._              //from what I recall changing this to JDBCProfile does *not* work. Must use specific driver.
  import slick.jdbc.HsqldbProfile.MappedJdbcType
  
  implicit def enumMapper = MappedJdbcType.base[Value,Char](_.id.toChar, this(_))
}

// The enumeration
object OrderExpiry extends JDBCCharEnumeration {
  val Day = Value('0', "Good for Day")
  val Open = Value('2', "At the Opening")
  val IoC = Value('3', "Immediate or Cancel")
  val FoK = Value('4', "Fill or Kill")
  val Close = Value('7', "At the Close")
}

// The case class
case class Order(expiryType: OrderExpiry)

// The TableQuery definition
class OrderRow(_tableTag: Tag) extends profile.api.Table[Order](_tableTag, Some("REXDB"), "BUS_ORDER") {
  /** Database column EXPIRY_TYPE SqlType(REXDB.ORDER_EXPIRY) which is a user-defined-type as CHAR in sql*/
  val expiryType: Rep[OrderExpiry] = column[OrderExpiry]("EXPIRY_TYPE")
}