How to create Composite-key for a Model in lift's mapper?
Вопрос
Does mapper allows creation of composite key in Models ? If yes, kindly give an example.
Решение
This is one example:
class FooBar extends LongKeyedMapper[FooBar] {
def getSingleton = FooBar
def primaryKeyField = id
object id extends MappedLongIndex(this)
object foo extends MappedLongForeignKey(this, Foo)
object bar extends MappedLongForeignKey(this, Bar)
}
object FooBar extends FooBar with LogKeyedMetaMapper[FooBar] {
override def dbIndexes = Index(foo, bar) :: super.dbIndexes
}
Example taken from the Lift mailing list
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