VideoDao.java

/*
 * 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.examples.mapper.killrvideo.video;

import com.datastax.oss.driver.api.core.PagingIterable;
import com.datastax.oss.driver.api.mapper.annotations.Dao;
import com.datastax.oss.driver.api.mapper.annotations.QueryProvider;
import com.datastax.oss.driver.api.mapper.annotations.Select;
import com.datastax.oss.driver.api.mapper.annotations.Update;
import com.datastax.oss.driver.api.mapper.entity.saving.NullSavingStrategy;
import java.util.UUID;

@Dao
public interface VideoDao {

  /** Simple selection by full primary key. */
  @Select
  Video get(UUID videoid);

  /**
   * Selection by partial primary key, this will return multiple rows.
   *
   * <p>Also, note that this queries a different table: DAOs are not limited to a single entity, the
   * return type of the method dictates what rows will be mapped to.
   */
  @Select
  PagingIterable<UserVideo> getByUser(UUID userid);

  /** Other selection by partial primary key, for another table. */
  @Select
  PagingIterable<LatestVideo> getLatest(String yyyymmdd);

  /** Other selection by partial primary key, for yet another table. */
  @Select
  PagingIterable<VideoByTag> getByTag(String tag);

  /**
   * Creating a video is a bit more complex: because of denormalization, it involves multiple
   * tables.
   *
   * <p>A query provider is a nice way to wrap all the queries in a single operation, and hide the
   * details from the DAO interface.
   */
  @QueryProvider(
      providerClass = CreateVideoQueryProvider.class,
      entityHelpers = {Video.class, UserVideo.class, LatestVideo.class, VideoByTag.class})
  void create(Video video);

  /**
   * Update using a template: the template must have its full primary key set; beyond that, any
   * non-null field will be considered as a value to SET on the target row.
   *
   * <p>Note that we specify the null saving strategy for emphasis, but this is the default.
   */
  @Update(nullSavingStrategy = NullSavingStrategy.DO_NOT_SET)
  void update(Video template);
}