rxin commented on code in PR #39144: URL: https://github.com/apache/spark/pull/39144#discussion_r1053874730
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveOrderByAll.scala: ########## @@ -0,0 +1,81 @@ +/* + * 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.catalyst.analysis + +import org.apache.spark.sql.catalyst.expressions.SortOrder +import org.apache.spark.sql.catalyst.plans.logical.{LogicalPlan, Sort} +import org.apache.spark.sql.catalyst.rules.Rule +import org.apache.spark.sql.catalyst.trees.TreePattern.{SORT, UNRESOLVED_ATTRIBUTE} + +/** + * Resolve "order by all" in the following SQL pattern: + * `select col1, col2 from table order by all`. + * + * It orders the query result by all columns, from left to right. The query above becomes: + * + * `select col1, col2 from table order by col1, col2` + * + * This should also support specifying asc/desc, and nulls first/last. + */ +object ResolveOrderByAll extends Rule[LogicalPlan] { + + val ALL = "ALL" + + /** + * An extractor to pull out the SortOrder field in the ORDER BY ALL clause. We pull out that + * SortOrder object so we can pass its direction and null ordering. + */ + object OrderByAll { + def unapply(s: Sort): Option[SortOrder] = { + // This only applies to global ordering. + if (!s.global) { + return None + } + // Don't do this if we have more than one order field. That means it's not order by all. + if (s.order.size != 1) { + return None + } + // Don't do this if there's a child field called ALL. That should take precedence. + if (s.child.output.exists(_.name.toUpperCase() == ALL)) { + return None + } + + s.order.find { so => + so.child match { + case a: UnresolvedAttribute => a.name.toUpperCase() == ALL + case _ => false + } + } + } + } + + override def apply(plan: LogicalPlan): LogicalPlan = plan.resolveOperatorsUpWithPruning( + _.containsAllPatterns(UNRESOLVED_ATTRIBUTE, SORT), ruleId) { + // This only makes sense if the children is resolved. Review Comment: nit: child, not children -- 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]
