Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/1981#discussion_r64741369
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/plan/logical/operators.scala
---
@@ -272,23 +272,46 @@ case class Join(
left.output ++ right.output
}
+ private object JoinFieldReference {
+
+ def apply(
+ name: String,
+ resultType: TypeInformation[_],
+ left: LogicalNode,
+ right: LogicalNode): JoinFieldReference = {
+
+ val joinInputField = left.output.zipWithIndex.find(_._1.name ==
name).map(_._2)
+
.orElse(right.output.zipWithIndex.find(_._1.name == name).map(x =>
left.output.length + x._2))
+ .getOrElse(
+ throw new NoSuchElementException(s"""Could
not find field: $name"""))
+ .asInstanceOf[Int]
+
+ new JoinFieldReference(name, resultType, left, right, joinInputField)
+ }
+
+ }
+
private case class JoinFieldReference(
--- End diff --
I am sorry, I think my last comment was confusing. Actually, I
misinterpreted the semantics of the `RelBuilder.field(int, int, String)`
method. I thought it would automatically add the offset of the left input. But
apparently it doesn't...
How about we change the `JoinFieldReference` to this:
```
private case class JoinFieldReference(
name: String,
resultType: TypeInformation[_],
left: LogicalNode,
right: LogicalNode) extends Attribute {
val isFromLeftInput = left.output.map(_.name).contains(name)
val (indexInInput, indexInJoin) = if (isFromLeftInput) {
val indexInLeft = left.output.map(_.name).indexOf(name)
(indexInLeft, indexInLeft)
} else {
val indexInRight = right.output.map(_.name).indexOf(name)
(indexInRight, indexInRight + left.output.length)
}
override def toString = s"'$name"
override def toRexNode(implicit relBuilder: RelBuilder): RexNode = {
// look up type of field
val fieldType = relBuilder.field(2, if (isFromLeftInput) 0 else 1,
name).getType()
// create a new RexInputRef with index offset
new RexInputRef(indexInJoin, fieldType)
}
override def withName(newName: String): Attribute = {
if (newName == name) {
this
} else {
JoinFieldReference(newName, resultType, left, right)
}
}
}
```
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