| /* |
| * 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.asterix.lang.aql.visitor; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.asterix.common.functions.FunctionConstants; |
| import org.apache.asterix.common.functions.FunctionSignature; |
| import org.apache.asterix.lang.aql.clause.ForClause; |
| import org.apache.asterix.lang.aql.expression.FLWOGRExpression; |
| import org.apache.asterix.lang.aql.visitor.base.AbstractAqlAstVisitor; |
| import org.apache.asterix.lang.common.base.Clause; |
| import org.apache.asterix.lang.common.base.Expression; |
| import org.apache.asterix.lang.common.clause.WhereClause; |
| import org.apache.asterix.lang.common.expression.CallExpr; |
| import org.apache.asterix.lang.common.expression.LiteralExpr; |
| import org.apache.asterix.lang.common.expression.VariableExpr; |
| import org.apache.asterix.lang.common.literal.StringLiteral; |
| import org.apache.asterix.lang.common.statement.DeleteStatement; |
| import org.apache.asterix.lang.common.statement.Query; |
| import org.apache.asterix.lang.common.struct.Identifier; |
| |
| public class AqlDeleteRewriteVisitor extends AbstractAqlAstVisitor<Void, Void> { |
| |
| @Override |
| public Void visit(DeleteStatement deleteStmt, Void visitArg) { |
| List<Expression> arguments = new ArrayList<Expression>(); |
| Identifier dataverseName = deleteStmt.getDataverseName(); |
| Identifier datasetName = deleteStmt.getDatasetName(); |
| String arg = dataverseName == null ? datasetName.getValue() |
| : dataverseName.getValue() + "." + datasetName.getValue(); |
| LiteralExpr argumentLiteral = new LiteralExpr(new StringLiteral(arg)); |
| arguments.add(argumentLiteral); |
| CallExpr callExpression = new CallExpr(new FunctionSignature(FunctionConstants.ASTERIX_NS, "dataset", 1), |
| arguments); |
| |
| List<Clause> clauseList = new ArrayList<Clause>(); |
| VariableExpr var = deleteStmt.getVariableExpr(); |
| Clause forClause = new ForClause(var, callExpression); |
| clauseList.add(forClause); |
| Clause whereClause = null; |
| Expression condition = deleteStmt.getCondition(); |
| if (condition != null) { |
| whereClause = new WhereClause(condition); |
| clauseList.add(whereClause); |
| } |
| VariableExpr returnExpr = new VariableExpr(var.getVar()); |
| returnExpr.setIsNewVar(false); |
| FLWOGRExpression flowgr = new FLWOGRExpression(clauseList, returnExpr); |
| Query query = new Query(false); |
| query.setBody(flowgr); |
| deleteStmt.setQuery(query); |
| return null; |
| } |
| |
| } |