content: /*
   * 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 com.datastax.oss.driver.api.mapper.annotations;
  
  import java.lang.annotation.ElementType;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Target;
  
  /**
   * Annotates the field or getter of an {@link Entity} property, to indicate that it's a clustering
   * column.
   *
   * <p>Example:
   *
   * <pre>
   * &#64;ClusteringColumn private int month;
   * </pre>
   *
   * This information is used by the mapper processor to generate default queries (for example a basic
   * {@link Select}).
   *
   * <p>If there are multiple clustering columns, you must specify {@link #value()} to indicate the
   * position of each property:
   *
   * <pre>
   * &#64;ClusteringColumn(1) private int month;
   * &#64;ClusteringColumn(2) private int day;
   * </pre>
   *
   * If you don't specify positions, or if there are duplicates, the mapper processor will issue a
   * compile-time error.
   *
   * <p>This annotation is mutually exclusive with {@link PartitionKey}.
   */
  @Target({ElementType.FIELD, ElementType.METHOD})
  @Retention(RetentionPolicy.RUNTIME)
  public @interface ClusteringColumn {
  
    /**
     * The position of the clustering column.
     *
     * <p>This is only required if there are multiple clustering columns. Positions are not strictly
     * required to be consecutive or start at a given index, but for clarity it is recommended to use
     * consecutive integers.
     */
    int value() default 0;
  }
  