Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/1958#discussion_r62682155
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/expressions/fieldExpression.scala
---
@@ -20,27 +20,98 @@ package org.apache.flink.api.table.expressions
import org.apache.calcite.rex.RexNode
import org.apache.calcite.tools.RelBuilder
-case class UnresolvedFieldReference(override val name: String) extends
LeafExpression {
+import org.apache.flink.api.common.typeinfo.TypeInformation
+import org.apache.flink.api.table.validate.ExprValidationResult
+
+object NamedExpression {
+ private val curId = new java.util.concurrent.atomic.AtomicInteger()
+ def newExprId: Int = curId.getAndIncrement()
+}
+
+trait NamedExpression extends Expression {
+ def name: String
+ def exprId: Int
+ def toAttribute: Attribute
+}
+
+abstract class Attribute extends LeafExpression with NamedExpression {
+ override def toAttribute: Attribute = this
+
+ def withName(newName: String): Attribute
+}
+
+case class UnresolvedFieldReference(name: String) extends Attribute {
+ override def exprId: Int = throw new UnresolvedException(s"calling
exprId on ${this.getClass}")
+
override def toString = "\"" + name
+ override def withName(newName: String): Attribute =
UnresolvedFieldReference(newName)
+
+ override def dataType: TypeInformation[_] =
+ throw new UnresolvedException(s"calling dataType on ${this.getClass}")
+
+ override def validateInput(): ExprValidationResult =
+ ExprValidationResult.ValidationFailure(s"Unresolved reference $name")
+}
+
+case class ResolvedFieldReference(
+ name: String,
+ dataType: TypeInformation[_])(
+ val exprId: Int = NamedExpression.newExprId) extends Attribute {
+
+ override def toString = s"'$name"
+
override def toRexNode(implicit relBuilder: RelBuilder): RexNode = {
relBuilder.field(name)
}
-}
-case class ResolvedFieldReference(override val name: String) extends
LeafExpression {
- override def toString = s"'$name"
+ override def withName(newName: String): Attribute = {
+ if (newName == name) {
+ this
+ } else {
+ ResolvedFieldReference(newName, dataType)(exprId)
+ }
+ }
}
-case class Naming(child: Expression, override val name: String) extends
UnaryExpression {
+case class Alias(child: Expression, name: String)
+ extends UnaryExpression with NamedExpression {
+ val exprId: Int = NamedExpression.newExprId
+
override def toString = s"$child as '$name"
override def toRexNode(implicit relBuilder: RelBuilder): RexNode = {
relBuilder.alias(child.toRexNode, name)
}
- override def makeCopy(anyRefs: Seq[AnyRef]): this.type = {
+ override def dataType: TypeInformation[_] = child.dataType
+
+ override def makeCopy(anyRefs: Array[AnyRef]): this.type = {
val child: Expression = anyRefs.head.asInstanceOf[Expression]
copy(child, name).asInstanceOf[this.type]
}
+
+ override def toAttribute: Attribute = {
+ if (valid) {
+ ResolvedFieldReference(name, child.dataType)(exprId)
+ } else {
+ UnresolvedFieldReference(name)
+ }
+ }
+}
+
+case class UnresolvedAlias(
+ child: Expression,
+ aliasName: Option[String] = None) extends UnaryExpression with
NamedExpression {
+
+ override def name: String =
+ throw new UnresolvedException("Invalid call to name on
UnresolvedAlias")
+ override def toAttribute: Attribute =
--- End diff --
can you add a new lines here?
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