gengliangwang commented on a change in pull request #35855: URL: https://github.com/apache/spark/pull/35855#discussion_r833446908
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveDefaultColumns.scala ########## @@ -0,0 +1,371 @@ +/* + * 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.AnalysisException +import org.apache.spark.sql.catalyst.TableIdentifier +import org.apache.spark.sql.catalyst.analysis.ResolveDefaultColumns._ +import org.apache.spark.sql.catalyst.catalog._ +import org.apache.spark.sql.catalyst.expressions._ +import org.apache.spark.sql.catalyst.optimizer.ConstantFolding +import org.apache.spark.sql.catalyst.parser.{CatalystSqlParser, ParseException} +import org.apache.spark.sql.catalyst.plans.logical._ +import org.apache.spark.sql.catalyst.rules.Rule +import org.apache.spark.sql.catalyst.trees.AlwaysProcess +import org.apache.spark.sql.internal.SQLConf +import org.apache.spark.sql.types._ + +/** + * This is a rule to process DEFAULT columns in statements such as CREATE/REPLACE TABLE. + * + * Background: CREATE TABLE and ALTER TABLE invocations support setting column default values for + * later operations. Following INSERT, and INSERT MERGE commands may then reference the value + * using the DEFAULT keyword as needed. + * + * Example: + * CREATE TABLE T(a INT DEFAULT 4, b INT NOT NULL DEFAULT 5); + * INSERT INTO T VALUES (1, 2); + * INSERT INTO T VALUES (1, DEFAULT); + * INSERT INTO T VALUES (DEFAULT, 6); + * SELECT * FROM T; + * (1, 2) + * (1, 5) + * (4, 6) + * + * @param catalog the catalog to use for looking up the schema of INSERT INTO table objects. + * @param insert the enclosing INSERT statement for which this rule is processing the query, if any. + */ +case class ResolveDefaultColumns( + catalog: SessionCatalog, + insert: Option[InsertIntoStatement] = None) extends Rule[LogicalPlan] { + override def apply(plan: LogicalPlan): LogicalPlan = plan.resolveOperatorsWithPruning( + AlwaysProcess.fn, ruleId) { + case _ if !SQLConf.get.enableDefaultColumns => plan + + case i@InsertIntoStatement(_, _, _, _, _, _) + if i.query.collectFirst { case u: UnresolvedInlineTable => u }.isDefined => + // Create a helper instance of this same rule with the `insert` argument populated as `i`. + // Then recursively apply it on the `query` of `i` to transform the result. This recursive + // application lets the below case matching against `UnresolvedInlineTable` to trigger + // anywhere that operator may appear in the descendants of `i.query`. + val helper = ResolveDefaultColumns(catalog, Some(i)) + val newQuery = helper.apply(i.query) + i.copy(query = newQuery) + + case table: UnresolvedInlineTable + if insert.isDefined && + table.rows.nonEmpty && table.rows.forall(_.size == table.rows(0).size) => + val expanded: UnresolvedInlineTable = addMissingDefaultColumnValues(table).getOrElse(table) + replaceExplicitDefaultColumnValues(expanded).getOrElse(table) + + case i@InsertIntoStatement(_, _, _, project: Project, _, _) + if !project.resolved => + val helper = ResolveDefaultColumns(catalog, Some(i)) + val replaced: Option[Project] = helper.replaceExplicitDefaultColumnValues(project) + if (replaced.isDefined) i.copy(query = replaced.get) else i + + case i@InsertIntoStatement(_, _, _, project: Project, _, _) + if project.resolved => + val helper = ResolveDefaultColumns(catalog, Some(i)) + val expanded: Project = helper.addMissingDefaultColumnValues(project).getOrElse(project) + val replaced: Option[Project] = helper.replaceExplicitDefaultColumnValues(expanded) + if (replaced.isDefined) i.copy(query = replaced.get) else i + } + + // Helper method to check if an expression is an explicit DEFAULT column reference. + private def isExplicitDefaultColumn(expr: Expression): Boolean = expr match { + case u: UnresolvedAttribute if u.name.equalsIgnoreCase(CURRENT_DEFAULT_COLUMN_NAME) => true + case _ => false + } + + // Helper method to check that an inline table has any explicit DEFAULT column references. + private def hasExplicitDefaultReferences(table: UnresolvedInlineTable): Boolean = Review comment: This method is not used. -- This is an automated message from the Apache Git Service. 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