試圖刪除DataFrame中的列,但我列出了其中包含點的列名,這些列名都是我逃過的。Spark 1.6:在DataFrame中刪除列,並使用轉義列名
我逃離之前,我的模式是這樣的:
root
|-- user_id: long (nullable = true)
|-- hourOfWeek: string (nullable = true)
|-- observed: string (nullable = true)
|-- raw.hourOfDay: long (nullable = true)
|-- raw.minOfDay: long (nullable = true)
|-- raw.dayOfWeek: long (nullable = true)
|-- raw.sensor2: long (nullable = true)
如果我試圖刪除列,我得到:
df = df.drop("hourOfWeek")
org.apache.spark.sql.AnalysisException: cannot resolve 'raw.hourOfDay' given input columns raw.dayOfWeek, raw.sensor2, observed, raw.hourOfDay, hourOfWeek, raw.minOfDay, user_id;
at org.apache.spark.sql.catalyst.analysis.package$AnalysisErrorAt.failAnalysis(package.scala:42)
at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1$$anonfun$apply$2.applyOrElse(CheckAnalysis.scala:60)
at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1$$anonfun$apply$2.applyOrElse(CheckAnalysis.scala:57)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformUp$1.apply(TreeNode.scala:319)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformUp$1.apply(TreeNode.scala:319)
at org.apache.spark.sql.catalyst.trees.CurrentOrigin$.withOrigin(TreeNode.scala:53)
請注意,我不甚至還試圖砸名字中有點的列。 因爲我似乎不能做太多不逃逸的列名,我轉換架構:
root
|-- user_id: long (nullable = true)
|-- hourOfWeek: string (nullable = true)
|-- observed: string (nullable = true)
|-- `raw.hourOfDay`: long (nullable = true)
|-- `raw.minOfDay`: long (nullable = true)
|-- `raw.dayOfWeek`: long (nullable = true)
|-- `raw.sensor2`: long (nullable = true)
,但似乎並沒有幫助。我仍然得到同樣的錯誤。
我試着轉義所有列名稱,並使用轉義名稱,但這也不起作用。
root
|-- `user_id`: long (nullable = true)
|-- `hourOfWeek`: string (nullable = true)
|-- `observed`: string (nullable = true)
|-- `raw.hourOfDay`: long (nullable = true)
|-- `raw.minOfDay`: long (nullable = true)
|-- `raw.dayOfWeek`: long (nullable = true)
|-- `raw.sensor2`: long (nullable = true)
df.drop("`hourOfWeek`")
org.apache.spark.sql.AnalysisException: cannot resolve 'user_id' given input columns `user_id`, `raw.dayOfWeek`, `observed`, `raw.minOfDay`, `raw.hourOfDay`, `raw.sensor2`, `hourOfWeek`;
at org.apache.spark.sql.catalyst.analysis.package$AnalysisErrorAt.failAnalysis(package.scala:42)
at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1$$anonfun$apply$2.applyOrElse(CheckAnalysis.scala:60)
是否有另一種方法可以刪除不會對此類型數據失敗的列?
有用的答案。但我還有一個類似的問題。假設我在Spark Dataframe中有大約100列。有什麼辦法從這個數據框中只選擇幾列,並用這些選定的列創建另一個數據框?像df2 = df1.select(df.col(「col1」,「col2」)) – JKC
我認爲這個https://stackoverflow.com/questions/36131716/scala-spark-dataframe-dataframe-select-multiple-columns -given -a-sequence-of-co回答你的問題 – MrE