Elasticsearch--查询

基本查询

• 两种查询方法

  • 查询条件设置在查询字符串中
  • 查询条件设置在请求体中 GET也可以设置

• 根据文档ID

 curl -X GET 127.0.0.1:9200/articles/article/1  # 查询文档id=1d的数据
 curl -X GET 127.0.0.1:9200/articles/article/1?_source=title,user_id  # 查询文档id=1d的数据, 只取出标题和用户id
 curl -X GET 127.0.0.1:9200/articles/article/1?_source=false   # 查询文档id=1d的数据,不取出任何基础数据

• 查询所有
  • 默认分页10条

curl -X GET 127.0.0.1:9200/articles/article/_search?_source=title,user_id

• 分页查询
  • from 起始
  • size 每页数量

curl -X GET 127.0.0.1:9200/articles/article/_search?_source=title,user_id&size=3  # 每页3条

curl -X GET 127.0.0.1:9200/articles/article/_search?_source=title,user_id&size=3&from=10  # 从第10条开始取, 取3条

• 全文检索
  • %20表示空格

# 文章标题匹配 "python web"
curl -X GET 127.0.0.1:9200/articles/article/_search?q=title:python%20web&_source=title,article_id&pretty  # 查询内容匹配"python web"的数据

# 文章标题和内容匹配 "python web"
curl -X GET 127.0.0.1:9200/articles/article/_search?q=title:python%20web,content:python%20web&_source=title,article_id&pretty

# 所有字段匹配"python web"
curl -X GET 127.0.0.1:9200/articles/article/_search?q=_all:python%20web&_source=title,article_id&pretty

高级查询

全文检索

• 根据分词后的结果进行查询, 按照得分排序
• match

curl -X GET 127.0.0.1:9200/articles/article/_search -d'
  {
      "query" : {
          "match" : {  # 表示全文检索
              "title" : "python web"  # 指定检索的字段
          }
      }
  }'

  curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d'
  {
      "from": 0,  # 指定分页
      "size": 5,
      "_source": ["article_id","title"],  # 指定返回的数据
      "query" : {
          "match" : {
              "title" : "python web"
          }
      }
  }'

  curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d'
 {
      "from": 0,
      "size": 5,
      "_source": ["article_id","title"],
      "query" : {
          "match" : {
              "_all" : "python web 编程"
          }
      }
 }'

短语查询

• 要求包含所有的词条, 不需要直接相连, 相对位置不能改变
• match_phrase

curl -X PUT 127.0.0.1:9200/articles/article/150000 -H 'Content-Type:application/json' -d '{
  "article_id": 150000,
  "title": "python is good",
  "status": 2
}'

curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d'
 {
      "from": 0,
      "size": 5,
      "_source": ["article_id","title"],
      "query" : {
          "match_phrase" : {
              "title" : "python good"
          }
      }
 }'

精确查找

• 不会分词, 必须能够匹配到词条(索引库中必须有该词条)
• term

curl -X PUT 127.0.0.1:9200/articles/article/150000 -H 'Content-Type:application/json' -d '
{
  "article_id": 150000,
  "user_id": 1,
  "title": "确实如此",  # 确实  实如  如此  
  "content": "python is good",
  "status": 2,
  "create_time": "2019-04-03"
}'


curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d'
    {
        "size": 5,
        "_source": ["title"],
        "query" : {
            "term" : {
                "title" : "确实如此" 
                }
            }
        }
    }'

• 范围查找 range
  • gt greater than 大于
  • gte greater than equel 大于等于
  • lt 小于
  • lte 小于等于
• 高亮显示
  • highlight
  • 结果中对指定的字段匹配到的位置进行<em>标识, 设置了html斜体标签
• 组合查询 bool
  • 逻辑运算
  • must
  • must_not
  • should or / 如果和must配合使用, 则只会变为加分项,并不强制要求
  • filter 直接过滤掉数据, 不进行评分

# 标题匹配"python web" 并且 内容匹配"python c"
curl -X GET 127.0.0.1:9200/articles/article/search?pretty -d '
  {
  "source": ["title", "user_id"],
  "query": {
      "bool": {
          "must": [
          {"match": {"title": "python web"}}, 
          {"match": {"content": "python c"}}] 
			}
  }
}
'

---

# 标题匹配"python web" 或者 内容匹配"python c"
curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d '
{
  "_source": ["title", "user_id"],
  "query": {
      "bool": {
          "should": [{"match": {"title": "python web"}}, {"match": {"content": "python c"}}],
      }
  }
}
'	

---

# (标题匹配"python web" 并且 内容匹配"python c") 并且 (状态 匹配2 或者 user_id 匹配1)      -> (A and B) and (C or D)
curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d '
{
  "_source": ["title", "user_id"],
  "query": {
      "bool": {
          "filter": {
              "bool": {
                "must": [{"match": {"title": "python web"}}, {"match": {"content": "python"}}],
                "should": [
                  {"match": {"status": 2}}, {"match": {"user_id": 1}}
                ]
              }
          }
      }
  }
}
'

filter和query的区别

• query匹配完会进行排序
• filter只判断是否满足要求, 不进行排序, 而且对于不满足要求的结果会进行缓存

要求 status=2 并且 title 匹配 “python web”

# 只使用query
curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d '
{
  "_source": ["title", "user_id"],
  "query": {
      "bool": {
          "must": [
              {"term": 
                  {"status": 2}
              },
              {"match": 
              	{"title": "python web"}
              }
          ]
      }
  }
}
'

# 先使用filter过滤, 再使用query排序
curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d '
{
  "_source": ["title", "user_id"],
  "query": {
      "bool": {
		      "must": [
              {"match": 
              	{"title": "python web"}
              }
          ],
      		"filter": {
          	"term": {"status": 2}
          }
      }
  }
}
'

• 排序

curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d'
  {
      "size": 5,
      "_source": ["article_id","title"],
      "query" : {
          "match" : {
              "_all" : "python web"
          }
      },
      "sort": [
          { "create_time":  { "order": "desc" }},
          { "_score": { "order": "desc" }}
      ]
  }'

• 提升权重boost

curl -X GET 127.0.0.1:9200/articles/article/_search?pretty -d'
  {
      "size": 5,
      "_source": ["article_id","title"],
      "query" : {
      		"must": [
            "match" : {
                "title" : {
                    "query": "python web",
                    "boost": 4
                }
            },
            "match": {
            		"content": "python web"
            }
      		]
          
      }
  }'