如何处理orientdb蓝图中的选项

Question

我正在使用Scala和OrientDB与Blueprint API。

libraryDependencies += "com.orientechnologies" % "orientdb-core" % "2.1.16"
libraryDependencies += "com.tinkerpop.blueprints" % "blueprints-core" % "2.6.0"
libraryDependencies += "com.orientechnologies" % "orientdb-graphdb" % "2.1.16"
libraryDependencies += "com.orientechnologies" % "orientdb-client" % "2.1.16"
libraryDependencies += "com.orientechnologies" % "orientdb-enterprise" % "2.1.16"

当我要存储Option [Int]类型的val（到整数类型）时的行为是这样的：

val vertex: Vertex = graph.addVertex("prova",null)
vertex.setProperty("foo",None) //It store an empty value

这种行为是正确的，但是如果我要存储Option [String]（对于String类型）我会得到这个：

val a: Option[String] = None
val vertex: Vertex = graph.addVertex("prova",null)
vertex.setProperty("foo",a) //It store "None" instead of empty, why?

如何避免这种情况？

解决

我已将此添加到配置

new OrientGraphFactory().setStandardElementConstraints(false)

我改变了这样的代码：

val a: Option[String] = None //or Some("foo")
val vertex: Vertex = graph.addVertex("prova",null)
vertex.setProperty("foo",a.orNull)