如何在lift的映射器中为模型创建Composite-key？

Question

mapper是否允许在模型中创建复合键？如果是，请举个例子。

Answer 1

这是一个例子：

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 
} 

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的示例