spark-sql-Expression-NamedExpression.adoc

NamedExpression

NamedExpression is a contract of Catalyst expressions that have a name, exprId, and optional qualifier.

package org.apache.spark.sql.catalyst.expressions

trait NamedExpression extends Expression {
  // only required methods that have no implementation
  def exprId: ExprId
  def name: String
  def newInstance(): NamedExpression
  def qualifier: Option[String]
  def toAttribute: Attribute
}

Table 1. NamedExpression Contract

Method	Description
exprId	Used when…​FIXME
name	Used when…​FIXME
qualifier	Used when…​FIXME

Creating ExprId — newExprId Object Method

newExprId: ExprId

newExprId…​FIXME

Note	newExprId is used when…​FIXME