48、初识搜索引擎_快速上机动手实战Query DSL搜索语法

1、一个例子让你明白什么是Query DSL

GET /_search
{
    "query": {
        "match_all": {}
    }
}

Query DSL 就是多条件组合搜索

2、Query DSL的基本语法

{
    QUERY_NAME: {
        ARGUMENT: VALUE,
        ARGUMENT: VALUE,...
    }
}

{
    QUERY_NAME: {
        FIELD_NAME: {
            ARGUMENT: VALUE,
            ARGUMENT: VALUE,...
        }
    }
}

示例：

GET /test_index/_doc/_search 
{
  "query": {
    "match": {
      "test_field": "test"
    }
  }
}

3、如何组合多个搜索条件

搜索需求：title必须包含elasticsearch，content可以包含elasticsearch也可以不包含，author_id必须不为111
index 数据如下：

{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 3,
    "max_score": 1,
    "hits": [
      {
        "_index": "website",
        "_type": "article",
        "_id": "2",
        "_score": 1,
        "_source": {
          "title": "my hadoop article",
          "content": "hadoop is very bad",
          "author_id": 111
        }
      },
      {
        "_index": "website",
        "_type": "article",
        "_id": "1",
        "_score": 1,
        "_source": {
          "title": "my elasticsearch article",
          "content": "es is very bad",
          "author_id": 110
        }
      },
      {
        "_index": "website",
        "_type": "article",
        "_id": "3",
        "_score": 1,
        "_source": {
          "title": "my elasticsearch article",
          "content": "es is very goods",
          "author_id": 111
        }
      }
    ]
  }
}

根据搜索需求搜索：

GET /website/_doc/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "match": {
            "title": "elasticsearch"
          }
        }
      ],
      "should": [
        {
          "match": {
            "content": "elasticsearch"
          }
        }
      ],
      "must_not": [
        {
          "match": {
            "author_id": 111
          }
        }
      ]
    }
  }
}

以下方式是复杂的组合搜索：

GET /test_index/_search
{
    "query": {
            "bool": {
                "must": { "match":   { "name": "tom" }},
                "should": [
                    { "match":       { "hired": true }},
                    { "bool": {
                        "must":      { "match": { "personality": "good" }},
                        "must_not":  { "match": { "rude": true }}
                    }}
                ],
                "minimum_should_match": 1
            }
    }
}

minimum should match：最低应该匹配