本文整理汇总了Scala中org.apache.spark.sql.catalyst.expressions.Alias类的典型用法代码示例。如果您正苦于以下问题：Scala Alias类的具体用法？Scala Alias怎么用？Scala Alias使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了Alias类的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Scala代码示例。
示例1: NaiveOrderResolution
//设置package包名称以及导入依赖的类
package by.skaryna.rules
import org.apache.spark.sql.catalyst.expressions.{Alias, AttributeReference, Expression, NamedExpression, SortOrder}
import org.apache.spark.sql.catalyst.plans.logical.{LogicalPlan, Project, Sort}
import org.apache.spark.sql.catalyst.rules.Rule
object NaiveOrderResolution extends Rule[LogicalPlan] {
def apply(plan: LogicalPlan): LogicalPlan = plan transform {
case Sort(Seq(order1), global1, Project(projectList, Sort(Seq(order2), global2, child2)))
if global1 == global2 && order1.direction == order2.direction &&
isOrderColumnRenamed(projectList, order1.child, order2.child) =>
val prunedProject = Project(projectList, child2)
Sort(Seq(order1), global1, prunedProject)
}
private[skaryna] def isOrderColumnRenamed(projectList: Seq[NamedExpression],
orderExpr1: Expression, orderExpr2: Expression): Boolean = {
val aliasMatch = projectList.collect {
case alias: Alias =>
alias.child == orderExpr2 && orderExpr1.isInstanceOf[AttributeReference] &&
alias.exprId == orderExpr1.asInstanceOf[AttributeReference].exprId
}
aliasMatch.contains(true)
}
}