| /* |
| * 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.iotdb.db.mpp.plan.analyze; |
| |
| import org.apache.iotdb.commons.path.PartialPath; |
| import org.apache.iotdb.commons.path.PathPatternTree; |
| import org.apache.iotdb.db.exception.sql.SemanticException; |
| import org.apache.iotdb.db.exception.sql.StatementAnalyzeException; |
| import org.apache.iotdb.db.mpp.plan.expression.Expression; |
| import org.apache.iotdb.db.mpp.plan.statement.Statement; |
| import org.apache.iotdb.db.mpp.plan.statement.component.ResultColumn; |
| import org.apache.iotdb.db.mpp.plan.statement.component.SelectComponent; |
| import org.apache.iotdb.db.mpp.plan.statement.crud.QueryStatement; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.stream.Collectors; |
| |
| /** |
| * This rewriter: |
| * |
| * <p>1. Concat prefix path in SELECT, WHERE, and WITHOUT NULL clause with the suffix path in the |
| * FROM clause. |
| * |
| * <p>2. Construct a {@link PathPatternTree}. |
| */ |
| public class ConcatPathRewriter { |
| |
| private PathPatternTree patternTree; |
| |
| public Statement rewrite(Statement statement, PathPatternTree patternTree) |
| throws StatementAnalyzeException { |
| QueryStatement queryStatement = (QueryStatement) statement; |
| this.patternTree = patternTree; |
| |
| // prefix paths in the FROM clause |
| List<PartialPath> prefixPaths = queryStatement.getFromComponent().getPrefixPaths(); |
| |
| if (queryStatement.isAlignByDevice()) { |
| queryStatement.getSelectComponent().getResultColumns().stream() |
| .map(ResultColumn::getExpression) |
| .forEach( |
| expression -> |
| ExpressionAnalyzer.constructPatternTreeFromExpression( |
| expression, prefixPaths, patternTree)); |
| } else { |
| // concat SELECT with FROM |
| List<ResultColumn> resultColumns = |
| concatSelectWithFrom( |
| queryStatement.getSelectComponent(), prefixPaths, queryStatement.isGroupByLevel()); |
| queryStatement.getSelectComponent().setResultColumns(resultColumns); |
| } |
| |
| // concat WHERE with FROM |
| if (queryStatement.getWhereCondition() != null) { |
| ExpressionAnalyzer.constructPatternTreeFromExpression( |
| queryStatement.getWhereCondition().getPredicate(), prefixPaths, patternTree); |
| } |
| |
| // concat HAVING with FROM |
| if (queryStatement.getHavingCondition() != null) { |
| ExpressionAnalyzer.constructPatternTreeFromExpression( |
| queryStatement.getHavingCondition().getPredicate(), prefixPaths, patternTree); |
| } |
| |
| return queryStatement; |
| } |
| |
| /** |
| * Concat the prefix path in the SELECT clause and the suffix path in the FROM clause into a full |
| * path pattern. And construct pattern tree. |
| */ |
| private List<ResultColumn> concatSelectWithFrom( |
| SelectComponent selectComponent, List<PartialPath> prefixPaths, boolean isGroupByLevel) |
| throws StatementAnalyzeException { |
| // resultColumns after concat |
| List<ResultColumn> resultColumns = new ArrayList<>(); |
| for (ResultColumn resultColumn : selectComponent.getResultColumns()) { |
| boolean needAliasCheck = resultColumn.hasAlias() && !isGroupByLevel; |
| List<Expression> resultExpressions = |
| ExpressionAnalyzer.concatExpressionWithSuffixPaths( |
| resultColumn.getExpression(), prefixPaths, patternTree); |
| if (needAliasCheck && resultExpressions.size() > 1) { |
| throw new SemanticException( |
| String.format( |
| "alias '%s' can only be matched with one time series", resultColumn.getAlias())); |
| } |
| resultColumns.addAll( |
| resultExpressions.stream() |
| .map( |
| expression -> |
| new ResultColumn( |
| expression, resultColumn.getAlias(), resultColumn.getColumnType())) |
| .collect(Collectors.toList())); |
| } |
| return resultColumns; |
| } |
| } |