EnricoMi commented on code in PR #36150: URL: https://github.com/apache/spark/pull/36150#discussion_r889077442
########## sql/core/src/main/scala/org/apache/spark/sql/Melt.scala: ########## @@ -0,0 +1,143 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.spark.sql + +import org.apache.spark.sql.catalyst.analysis.{AnsiTypeCoercion, TypeCoercion, UnresolvedAttribute} +import org.apache.spark.sql.catalyst.expressions.{AttributeReference, Cast, Expression, Literal, NamedExpression} +import org.apache.spark.sql.catalyst.expressions.objects.AssertNotNull +import org.apache.spark.sql.catalyst.plans.logical.Expand +import org.apache.spark.sql.functions.col +import org.apache.spark.sql.internal.SQLConf +import org.apache.spark.sql.types.{DataType, StringType} + +private[sql] object Melt { + def of[_]( + ds: Dataset[_], + ids: Seq[String], + values: Seq[String], + dropNulls: Boolean, + variableColumnName: String, + valueColumnName: String): DataFrame = { Review Comment: `Melt` is now a `LogicalPlan` with some rules in the analyser to melt all value columns except for the id columns if no value columns are given. The `Melt` logical plan is replaced by the equivalent `Expand` operation during analysis, once ids columns, value columns and output value type are resolved. This is much cleaner now, and allows for expressions, structs and `*` for id and value columns. Thanks for the pointers! -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
