Насколько мне известно, это должно работать ..
class StringCodes extends KeyedMapper[String,StringCodes] {
def getSingleton = StringCodes
def primaryKeyField = languageCd
object strCd extends MappedStringIndex(this,5)
{
override def writePermission_? = true // if u want to set it via your code, keep this true
override def dbAutogenerated_? = false
override def dbNotNull_? = true
override def dbColumnName="str_cd"
}
....