Description
DataFrame lets you create multiple columns with the same name, which causes problems when you try to refer to columns by name.
Proposal: If a column is added to a DataFrame with a column of the same name, then the new column should replace the old column.
scala> val df = sc.parallelize(Array(1,2,3)).toDF("x") df: org.apache.spark.sql.DataFrame = [x: int] scala> val df3 = df.withColumn("x", df("x") + 1) df3: org.apache.spark.sql.DataFrame = [x: int, x: int] scala> df3.collect() res1: Array[org.apache.spark.sql.Row] = Array([1,2], [2,3], [3,4]) scala> df3("x") org.apache.spark.sql.AnalysisException: Reference 'x' is ambiguous, could be: x, x.; at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan.resolve(LogicalPlan.scala:216) at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan.resolve(LogicalPlan.scala:121) at org.apache.spark.sql.DataFrame.resolve(DataFrame.scala:161) at org.apache.spark.sql.DataFrame.col(DataFrame.scala:436) at org.apache.spark.sql.DataFrame.apply(DataFrame.scala:426) at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:26) at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:31) at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:33) at $iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:35) at $iwC$$iwC$$iwC$$iwC.<init>(<console>:37) at $iwC$$iwC$$iwC.<init>(<console>:39) at $iwC$$iwC.<init>(<console>:41) at $iwC.<init>(<console>:43) at <init>(<console>:45) at .<init>(<console>:49) at .<clinit>(<console>) at .<init>(<console>:7) at .<clinit>(<console>) at $print(<console>) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.spark.repl.SparkIMain$ReadEvalPrint.call(SparkIMain.scala:1065) at org.apache.spark.repl.SparkIMain$Request.loadAndRun(SparkIMain.scala:1338) at org.apache.spark.repl.SparkIMain.loadAndRunReq$1(SparkIMain.scala:840) at org.apache.spark.repl.SparkIMain.interpret(SparkIMain.scala:871) at org.apache.spark.repl.SparkIMain.interpret(SparkIMain.scala:819) at org.apache.spark.repl.SparkILoop.reallyInterpret$1(SparkILoop.scala:856) at org.apache.spark.repl.SparkILoop.interpretStartingWith(SparkILoop.scala:901) at org.apache.spark.repl.SparkILoop.command(SparkILoop.scala:813) at org.apache.spark.repl.SparkILoop.processLine$1(SparkILoop.scala:656) at org.apache.spark.repl.SparkILoop.innerLoop$1(SparkILoop.scala:664) at org.apache.spark.repl.SparkILoop.org$apache$spark$repl$SparkILoop$$loop(SparkILoop.scala:669) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1.apply$mcZ$sp(SparkILoop.scala:996) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1.apply(SparkILoop.scala:944) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1.apply(SparkILoop.scala:944) at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135) at org.apache.spark.repl.SparkILoop.org$apache$spark$repl$SparkILoop$$process(SparkILoop.scala:944) at org.apache.spark.repl.SparkILoop.process(SparkILoop.scala:1058) at org.apache.spark.repl.Main$.main(Main.scala:31) at org.apache.spark.repl.Main.main(Main.scala) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:569) at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:166) at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:189) at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:110) at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
Attachments
Issue Links
- relates to
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SPARK-10073 Python withColumn for existing column name not consistent with scala
- Resolved
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SPARK-12204 Implement drop method for DataFrame in SparkR
- Resolved
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SPARK-6634 Allow replacing columns in Transformers
- Resolved
- links to