es - elasticsearch mapping - parameters - copy_to

世界上并没有完美的程序，但是我们并不因此而沮丧，因为写程序就是一个不断追求完美的过程。

问 ：copy_to有什么特点？
答 ：

问 ：copy_to如何使用？
答 ：

# copy_to

PUT /copy_to_test
{
  "mappings" : {
    "properties" : {
      "first_name" : {
        "type"    : "text",
        "copy_to" : "full_name"
      },
      "last_name"  : {
        "type"    : "text",
        "copy_to" : ["full_name", "extra_name"]
      },
      "full_name"  : {
        "type" : "text"
      },
      "extra_name" : {
        "type" : "text"
      }
    }
  }
}

# 索引
POST /copy_to_test/_doc/1
{
  "first_name" : "hello",
  "last_name"  : "good"
}

# 搜索
GET /copy_to_test/_search
{
  "query" : {
    "match" : {
      "full_name" : {
        "query"    : "hello good",
        "operator" : "and"
      }
    }
  }
}

# 结果
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.5753642,
    "hits" : [
      {
        "_index" : "copy_to_test",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.5753642,
        "_source" : {
          "first_name" : "hello",
          "last_name" : "good"
        }
      }
    ]
  }
}


# 搜索
GET /copy_to_test/_search
{
  "query" : {
    "match" : {
      "extra_name" : "good"
    }
  }
}

# 结果
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.2876821,
    "hits" : [
      {
        "_index" : "copy_to_test",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.2876821,
        "_source" : {
          "first_name" : "hello",
          "last_name" : "good"
        }
      }
    ]
  }
}