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/*
* Copyright DataStax, Inc.
*
* Licensed 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 com.datastax.driver.core;
/**
* The result of a query.
*
* The retrieval of the rows of a ResultSet is generally paged (a first page of result is fetched
* and the next one is only fetched once all the results of the first one has been consumed). The
* size of the pages can be configured either globally through {@link QueryOptions#setFetchSize} or
* per-statement with {@link Statement#setFetchSize}. Though new pages are automatically (and
* transparently) fetched when needed, it is possible to force the retrieval of the next page early
* through {@link #fetchMoreResults}. Please note however that this ResultSet paging is not
* available with the version 1 of the native protocol (i.e. with Cassandra 1.2 or if version 1 has
* been explicitly requested through {@link Cluster.Builder#withProtocolVersion}). If the protocol
* version 1 is in use, a ResultSet is always fetched in it's entirely and it's up to the client to
* make sure that no query can yield ResultSet that won't hold in memory.
*
*
Note that this class is not thread-safe.
*/
public interface ResultSet extends PagingIterable {
// redeclared only to make clirr happy
@Override
Row one();
/**
* Returns the columns returned in this ResultSet.
*
* @return the columns returned in this ResultSet.
*/
public ColumnDefinitions getColumnDefinitions();
/**
* If the query that produced this ResultSet was a conditional update, return whether it was
* successfully applied.
*
* This is equivalent to calling:
*
*
*
*
* rs.one().getBool("[applied]");
*
*
* Except that this method peeks at the next row without consuming it.
*
* For consistency, this method always returns {@code true} for non-conditional queries
* (although there is no reason to call the method in that case). This is also the case for
* conditional DDL statements ({@code CREATE KEYSPACE... IF NOT EXISTS}, {@code CREATE TABLE... IF
* NOT EXISTS}), for which Cassandra doesn't return an {@code [applied]} column.
*
*
Note that, for versions of Cassandra strictly lower than 2.0.9 and 2.1.0-rc2, a server-side
* bug (CASSANDRA-7337) causes this method to always return {@code true} for batches containing
* conditional queries.
*
* @return if the query was a conditional update, whether it was applied. {@code true} for other
* types of queries.
* @see CASSANDRA-7337
*/
public boolean wasApplied();
}