| /* |
| * 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.linq4j; |
| |
| import org.apache.calcite.linq4j.tree.Expression; |
| |
| import java.lang.reflect.Type; |
| |
| /** |
| * Partial implementation of {@link QueryProvider}. |
| * |
| * <p>Derived class needs to implement {@link #executeQuery}.</p> |
| */ |
| public abstract class QueryProviderImpl implements QueryProvider { |
| /** |
| * Creates a QueryProviderImpl. |
| */ |
| public QueryProviderImpl() { |
| super(); |
| } |
| |
| public <T> Queryable<T> createQuery(Expression expression, Class<T> rowType) { |
| return new QueryableImpl<>(this, rowType, expression); |
| } |
| |
| public <T> Queryable<T> createQuery(Expression expression, Type rowType) { |
| return new QueryableImpl<>(this, rowType, expression); |
| } |
| |
| public <T> T execute(Expression expression, Class<T> type) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public <T> T execute(Expression expression, Type type) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Binds an expression to this query provider. |
| * |
| * @param <T> element type |
| */ |
| public static class QueryableImpl<T> extends BaseQueryable<T> { |
| public QueryableImpl(QueryProviderImpl provider, Type elementType, |
| Expression expression) { |
| super(provider, elementType, expression); |
| } |
| |
| @Override public String toString() { |
| return "Queryable(expr=" + expression + ")"; |
| } |
| } |
| } |