flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-6196) Support dynamic schema in Table Function
Date Wed, 19 Apr 2017 08:24:41 GMT

    [ https://issues.apache.org/jira/browse/FLINK-6196?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15974305#comment-15974305
] 

ASF GitHub Bot commented on FLINK-6196:
---------------------------------------

Github user clarkyzl commented on a diff in the pull request:

    https://github.com/apache/flink/pull/3623#discussion_r112141809
  
    --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/utils/UserDefinedFunctionUtils.scala
---
    @@ -382,7 +381,10 @@ object UserDefinedFunctionUtils {
           implicitResultType: TypeInformation[_],
           params: Expression*): TableFunctionCall = {
         val arguments = transformLiteralExpressions(params: _*)
    -    val userDefinedResultType = tableFunction.getResultType(arguments)
    +    val typeInformations = params.map { param =>
    +      if (param.valid) param.resultType else null
    --- End diff --
    
    Actually. The `param.valid` here is to skip the `UnresolvedFieldReference`.
    For example.
    ```
        val result = in
          .join(funcDyn('c, 1) as 'name)
          .select('c, 'name)
    ```
    will throw a `UnresolvedFieldReference`
    ```
    org.apache.flink.table.api.UnresolvedException: Calling resultType on class org.apache.flink.table.expressions.UnresolvedFieldReference.
    
    	at org.apache.flink.table.expressions.UnresolvedFieldReference.resultType(fieldExpression.scala:45)
    	at org.apache.flink.table.functions.utils.UserDefinedFunctionUtils$$anonfun$10.apply(UserDefinedFunctionUtils.scala:385)
    	at org.apache.flink.table.functions.utils.UserDefinedFunctionUtils$$anonfun$10.apply(UserDefinedFunctionUtils.scala:384)
    	at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
    	at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
    	at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
    	at scala.collection.mutable.WrappedArray.foreach(WrappedArray.scala:34)
    	at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
    	at scala.collection.AbstractTraversable.map(Traversable.scala:105)
    	at org.apache.flink.table.functions.utils.UserDefinedFunctionUtils$.buildTableFunctionCall(UserDefinedFunctionUtils.scala:384)
    	at org.apache.flink.table.functions.TableFunction.apply(TableFunction.scala:91)
    	at org.apache.flink.table.runtime.dataset.DataSetUserDefinedFunctionITCase.testDynamicSchema(DataSetUserDefinedFunctionITCase.scala:127)
    ```
    Because `'c` is an `Expression` which has't been resolved.


> Support dynamic schema in Table Function
> ----------------------------------------
>
>                 Key: FLINK-6196
>                 URL: https://issues.apache.org/jira/browse/FLINK-6196
>             Project: Flink
>          Issue Type: Improvement
>          Components: Table API & SQL
>            Reporter: Zhuoluo Yang
>            Assignee: Zhuoluo Yang
>
> In many of our use cases. We have to decide the schema of a UDTF at the run time. For
example. udtf('c1, c2, c3') will generate three columns for a lateral view. 
> Most systems such as calcite and hive support this feature. However, the current implementation
of flink didn't implement the feature correctly.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Mime
View raw message