我是Spark和Cassandra的新手。我使用此代码,但它给我错误。
val dfprev = df.select(col = "se","hu")
val a = dfprev.select("se")
val b = dfprev.select("hu")
val collection = sc.parallelize(Seq(a,b))
collection.saveToCassandra("keyspace", "table", SomeColumns("se","hu"))
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当我在上输入此代码时savetocassandra,它给我错误,错误是:
java.lang.IllegalArgumentException:不允许多个带有相同数量参数的构造方法。com.datastax.spark.connector.util.Reflect $ .methodSymbol(Reflect.scala:16)com.datastax.spark.connector.util.ReflectionUtil $ .constructorParams(ReflectionUtil.scala:63)com.datastax.spark .connector.mapper.DefaultColumnMapper。(DefaultColumnMapper.scala:45)位于com.datastax.spark.connector.mapper.LowPriorityColumnMapper $ class.defaultColumnMapper(ColumnMapper.scala:51),位于om.datastax.spark.connector.mapper.ColumnMapper $ .defaultColumnMapper(ColumnMapper.scala:55)