创建使用幻影斯卡拉DSL
问题描述:
在卡桑德拉的模式我写了这个代码创建使用幻影斯卡拉DSL
case class User(id: Int, gender: String, age: Int, occupation: String, zipCode: String)
object Defaults {
val hosts = Seq("172.17.0.9")
val Connector = ContactPoints(hosts).keySpace("Movies")
}
class MyDatabase(val keyspace: KeySpaceDef) extends com.websudos.phantom.db.DatabaseImpl(keyspace) {
object users extends Users with keyspace.Connector
}
object MyDatabase extends MyDatabase(Defaults.Connector)
class Users extends CassandraTable[Users, User] {
object id extends IntColumn(this) with PartitionKey[Int]
object age extends IntColumn(this) with Index[Int]
object gender extends StringColumn(this) with Index[String]
object occupation extends StringColumn(this) with Index[String]
object zipCode extends StringColumn(this) with Index[String]
def fromRow(row: Row) : User = {
User(
row(id),
row(gender),
row(age),
row(occupation),
row(zipCode)
)
}
}
object Users extends Users with RootConnector {
def store(user: User) : Future[ResultSet] = {
insert
.value(_.id, user.id)
.value(_.gender, user.gender)
.value(_.age, user.age)
.value(_.occupation, user.occupation)
.value(_.zipCode, user.zipCode)
.consistencyLevel_=(ConsistencyLevel.ALL)
.future()
}
def getById(id: Int) : Future[Option[User]] = {
select.where(_.id eqs id).one()
}
}
但是,当我编译此,我得到一个错误。
Object creation impossible, since member session: Session in
com.websudos.phantom.connectors.RootConnector is not defined; member space:
KeySpace in com.websudos.phantom.connectors.RootConnector is not defined.
我也看到其他错误
[error] /Users/U/MyProjects/src/main/scala-2.11/com/abhi/MovieLensDataPreperation.scala:180: com.websudos.phantom.dsl.Row does not take parameters
[error] row(id),
[error] ^
[error] /Users/U/MyProjects/src/main/scala-2.11/com/abhi/MovieLensDataPreperation.scala:181: com.websudos.phantom.dsl.Row does not take parameters
[error] row(gender),
[error] ^
[error] /Users/U/MyProjects/src/main/scala-2.11/com/abhi/MovieLensDataPreperation.scala:182: com.websudos.phantom.dsl.Row does not take parameters
[error] row(age),
[error] ^
[error] /Users/U/MyProjects/src/main/scala-2.11/com/abhi/MovieLensDataPreperation.scala:183: com.websudos.phantom.dsl.Row does not take parameters
[error] row(occupation),
[error] ^
[error] /Users/U/MyProjects/src/main/scala-2.11/com/abhi/MovieLensDataPreperation.scala:184: com.websudos.phantom.dsl.Row does not take parameters
[error] row(zipCode)
[error] ^
[error] 5 errors found
[error] (compile:compileIncremental) Compilation failed
答
既然你已经定义ID,性别,年龄等栏目,你应该从一排这样的提取值:
def fromRow(row: Row) : User = {
User(
id(row),
gender(row),
age(row),
occupation(row),
zipCode(row)
)
}
我认为你应该再次阅读我的教程,你没有按照DSL的结构,你没有提供一个会议,你应该。你也没有使用'Database'实现,这真的很有帮助。小的事情,但通过这将帮助你加快速度。你的'用户'对象应该是一个名为'ConcreteUsers'的类,这就是'MyDatabase'下''用户'字段应该扩展的东西,否则你将没有任何方法。 http://websudos.com/blog/post/a-series-on-phantom-part-1-getting-started-with-phantom – flavian
谢谢Flavian。我改变了我的实现基于这里的代码https://github.com/thiagoandrade6/cassandra-phantom/blob/master/src/main/scala/com/cassandra/phantom/modeling/model/GenericSongsModel.scala现在它更好。不过,我还有另一个劫持。 http://*.com/questions/35692508/creating-model-for-cassandra-using-phantom-dsl –
我也回答了一个。 – flavian