viirya commented on a change in pull request #29587: URL: https://github.com/apache/spark/pull/29587#discussion_r489539877
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveUnion.scala ########## @@ -17,29 +17,168 @@ package org.apache.spark.sql.catalyst.analysis +import scala.collection.mutable + import org.apache.spark.sql.AnalysisException -import org.apache.spark.sql.catalyst.expressions.{Alias, Literal} +import org.apache.spark.sql.catalyst.expressions.{Alias, Attribute, CreateNamedStruct, Expression, GetStructField, If, IsNull, KnownNotNull, Literal, NamedExpression, WithFields} import org.apache.spark.sql.catalyst.optimizer.CombineUnions import org.apache.spark.sql.catalyst.plans.logical.{LogicalPlan, Project, Union} import org.apache.spark.sql.catalyst.rules.Rule import org.apache.spark.sql.internal.SQLConf +import org.apache.spark.sql.types._ import org.apache.spark.sql.util.SchemaUtils +import org.apache.spark.unsafe.types.UTF8String /** * Resolves different children of Union to a common set of columns. */ object ResolveUnion extends Rule[LogicalPlan] { - private def unionTwoSides( + /** + * This method sorts columns in a struct expression based on column names. + */ + private def sortStructFields(expr: Expression): Expression = { + assert(expr.dataType.isInstanceOf[StructType]) + + val existingExprs = expr.dataType.asInstanceOf[StructType].fieldNames.zipWithIndex.map { + case (name, i) => (name, GetStructField(KnownNotNull(expr), i).asInstanceOf[Expression]) + }.sortBy(_._1).flatMap(pair => Seq(Literal(pair._1), pair._2)) + + val newExpr = CreateNamedStruct(existingExprs) + if (expr.nullable) { + If(IsNull(expr), Literal(null, newExpr.dataType), newExpr) + } else { + newExpr + } + } + + private def sortStructFields(fieldExprs: Seq[Expression]): Seq[Expression] = { + fieldExprs.grouped(2).map { e => + Seq(e.head, e.last) + }.toSeq.sortBy { pair => + assert(pair(0).isInstanceOf[Literal]) + pair(0).eval().asInstanceOf[UTF8String].toString + }.flatten + } + + /** + * This helper method sorts fields in a `WithFields` expression by field name. + */ + private def sortStructFieldsInWithFields(expr: Expression): Expression = expr transformUp { + case w: WithFields if w.resolved => + w.evalExpr match { + case i @ If(IsNull(_), _, CreateNamedStruct(fieldExprs)) => + val sorted = sortStructFields(fieldExprs) + val newStruct = CreateNamedStruct(sorted) + i.copy(trueValue = Literal(null, newStruct.dataType), falseValue = newStruct) + case CreateNamedStruct(fieldExprs) => + val sorted = sortStructFields(fieldExprs) + val newStruct = CreateNamedStruct(sorted) + newStruct + case other => + throw new AnalysisException(s"`WithFields` has incorrect eval expression: $other") Review comment: Yea, I think so. Or we change `WithFields` but forget to update here. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org