| /* |
| * 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.calcite.rel; |
| |
| /** |
| * Exception that indicates that a relational expression would be invalid |
| * with given parameters. |
| * |
| * <p>This exception is thrown by the constructor of a subclass of |
| * {@link RelNode} when given parameters it cannot accept. For example, |
| * {@code EnumerableJoinRel} can only implement equi-joins, so its constructor |
| * throws {@code InvalidRelException} when given the condition |
| * {@code input0.x - input1.y = 2}.</p> |
| * |
| * <p>Because the exception is checked (i.e. extends {@link Exception} but not |
| * {@link RuntimeException}), constructors that throw this exception will |
| * declare this exception in their {@code throws} clause, and rules that create |
| * those relational expressions will need to handle it. Usually a rule will |
| * not take the exception personally, and will fail to match. The burden of |
| * checking is removed from the rule, which means less code for the author of |
| * the rule to maintain.</p> |
| * |
| * <p>The caller that receives an {@code InvalidRelException} (typically a rule |
| * attempting to create a relational expression) should log it at |
| * the DEBUG level.</p> |
| */ |
| public class InvalidRelException extends Exception { |
| /** |
| * Creates an InvalidRelException. |
| */ |
| public InvalidRelException(String message) { |
| super(message); |
| } |
| |
| /** |
| * Creates an InvalidRelException with a cause. |
| */ |
| public InvalidRelException(String message, Throwable cause) { |
| super(message, cause); |
| } |
| } |
| |
| // End InvalidRelException.java |