maropu commented on a change in pull request #29587: URL: https://github.com/apache/spark/pull/29587#discussion_r479979494
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveUnion.scala ########## @@ -17,29 +17,97 @@ 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, Expression, 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 /** * Resolves different children of Union to a common set of columns. */ object ResolveUnion extends Rule[LogicalPlan] { - private def unionTwoSides( + /** + * Adds missing fields recursively into given `col` expression, based on the target `StructType`. + * For example, given `col` as "a struct<a:int, b:int>, b int" and `target` as + * "a struct<a:int, b:int, c: long>, b int, c string", this method should add `a.c` and `c` to + * `col` expression. + */ + private def addFields(col: NamedExpression, target: StructType): Option[Expression] = { + require(col.dataType.isInstanceOf[StructType], "Only support StructType.") Review comment: `assert` instead? ---------------------------------------------------------------- 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