elasticsearch term match 查询
1. 准备数据
PUT h1/doc/1
{"name": "rose","gender": "female","age": 18,"tags": ["白", "漂亮", "高"]
}PUT h1/doc/2
{"name": "lila","gender": "female","age": 18,"tags": ["黑", "漂亮", "高"]
}PUT h1/doc/3
{"name": "john","gender": "male","age": 18,"tags": ["黑", "帅", "高"]
}
运行结果:
{"_index" : "h1","_type" : "doc","_id" : "1","_version" : 1,"result" : "created","_shards" : {"total" : 2,"successful" : 1,"failed" : 0},"_seq_no" : 0,"_primary_term" : 1
}
2. match 查询
2.1 match 按条件查询
# 查询性别是男性的结果
GET h1/doc/_search
{"query": {"match": {"gender": "male"}}
}
查询结果:
{"took" : 59,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 1,"max_score" : 0.2876821,"hits" : [{"_index" : "h1", # 索引"_type" : "doc", # 文档类型"_id" : "3", # 文档唯一 id"_score" : 0.2876821, # 打分机制打出来的分数"_source" : { # 查询结果"name" : "john","gender" : "male","age" : 18,"tags" : ["黑","帅","高"]}}]}
}
2.2 match_all 查询全部
# 查询 h1 中所有文档
GET h1/doc/_search
{"query": {"match_all": {}}
}
match_all
的值为空,表示没有查询条件,那就是查询全部。就像select * from table_name
一样。
查询结果:
{"took" : 2,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 3,"max_score" : 1.0,"hits" : [{"_index" : "h1","_type" : "doc","_id" : "2","_score" : 1.0,"_source" : {"name" : "lila","gender" : "female","age" : 18,"tags" : ["黑","漂亮","高"]}},{"_index" : "h1","_type" : "doc","_id" : "1","_score" : 1.0,"_source" : {"name" : "rose","gender" : "female","age" : 18,"tags" : ["白","漂亮","高"]}},{"_index" : "h1","_type" : "doc","_id" : "3","_score" : 1.0,"_source" : {"name" : "john","gender" : "male","age" : 18,"tags" : ["黑","帅","高"]}}]}
}
2.3 match_phrase 短语查询
match
查询时散列映射,包含了我们希望搜索的字段和字符串,即只要文档中有我们希望的那个关键字,但也会带来一些问题。
es
会将文档中的内容进行拆分,对于英文来说可能没有太大的影响,但是中文短语就不太适用,一旦拆分就会失去原有的含义,比如以下:
1、准备数据:
PUT t1/doc/1
{"title": "中国是世界上人口最多的国家"
}PUT t1/doc/2
{"title": "美国是世界上军事实力最强大的国家"
}PUT t1/doc/3
{"title": "北京是中国的首都"
}
2、先使用 match
查询含有中国的文档:
GET t1/doc/_search
{"query": {"match": {"title": "中国"}}
}
查询结果:
{"took" : 5,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 3,"max_score" : 0.68324494,"hits" : [{"_index" : "t1","_type" : "doc","_id" : "1","_score" : 0.68324494,"_source" : {"title" : "中国是世界上人口最多的国家"}},{"_index" : "t1","_type" : "doc","_id" : "3","_score" : 0.5753642,"_source" : {"title" : "北京是中国的首都"}},{"_index" : "t1","_type" : "doc","_id" : "2","_score" : 0.39556286,"_source" : {"title" : "美国是世界上军事实力最强大的国家"}}]}
}
发现三篇文档都被返回,与我们的预期有偏差;这是因为 title
中的内容被拆分成一个个单独的字,而 id=2
的文档包含了 国 字也符合,所以也被返回了。es
自带的中文分词处理不太好用,后面可以使用 ik
中文分词器来处理。
3、match_phrase
查询短语
不过可以使用 match_phrase
来匹配短语,将上面的 match
换成 match_phrase
试试:
# 短语查询
GET t1/doc/_search
{"query": {"match_phrase": {"title": "中国"}}
}
查询结果:
{"took" : 2,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 2,"max_score" : 0.5753642,"hits" : [{"_index" : "t1","_type" : "doc","_id" : "1","_score" : 0.5753642,"_source" : {"title" : "中国是世界上人口最多的国家"}},{"_index" : "t1","_type" : "doc","_id" : "3","_score" : 0.5753642,"_source" : {"title" : "北京是中国的首都"}}]}
}
4、slop
间隔查询
当我们要查询的短语,中间有别的词时,可以使用 slop
来跳过。比如上述要查询 中国世界,这个短语中间被 是 隔开了,这时可以使用 slop
来跳过,相当于正则中的中国.*?世界
:
# 短语查询,查询中国世界,加 slop
GET t1/doc/_search
{"query": {"match_phrase": {"title": {"query": "中国世界","slop": 1}}}
}
查询结果:
{"took" : 4,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 1,"max_score" : 0.7445889,"hits" : [{"_index" : "t1","_type" : "doc","_id" : "1","_score" : 0.7445889,"_source" : {"title" : "中国是世界上人口最多的国家"}}]}
}
2.4 match_phrase_prefix 最左前缀查询
场景:当我们要查询的词只能想起前几个字符时
# 最左前缀查询,查询名字为 rose 的文档
GET h1/doc/_search
{"query": {"match_phrase_prefix": {"name": "ro"}}
}
查询结果:
{"took" : 1,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 1,"max_score" : 0.2876821,"hits" : [{"_index" : "h1","_type" : "doc","_id" : "1","_score" : 0.2876821,"_source" : {"name" : "rose","gender" : "female","age" : 18,"tags" : ["白","漂亮","高"]}}]}
}
限制结果集
最左前缀查询很费性能,返回的是一个很大的集合,一般很少使用,使用的时候最好对结果集进行限制,max_expansions
参数可以设置最大的前缀扩展数量:
# 最左前缀查询
GET h1/doc/_search
{"query": {"match_phrase_prefix": {"gender": {"query": "fe","max_expansions": 1}}}
}
查询结果:
{"took" : 2,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 2,"max_score" : 0.2876821,"hits" : [{"_index" : "h1","_type" : "doc","_id" : "2","_score" : 0.2876821,"_source" : {"name" : "lila","gender" : "female","age" : 18,"tags" : ["黑","漂亮","高"]}},{"_index" : "h1","_type" : "doc","_id" : "1","_score" : 0.2876821,"_source" : {"name" : "rose","gender" : "female","age" : 18,"tags" : ["白","漂亮","高"]}}]}
}
2.5 multi_match 多字段查询
1、准备数据:
# 多字段查询
PUT t3/doc/1
{"title": "maggie is beautiful girl","desc": "beautiful girl you are beautiful so"
}PUT t3/doc/2
{"title": "beautiful beach","desc": "I like basking on the beach,and you? beautiful girl"
}
2、查询包含 beautiful
字段的文档:
GET t3/doc/_search
{"query": {"multi_match": {"query": "beautiful", # 要查询的词"fields": ["desc", "title"] # 要查询的字段}}
}
还可以当做 match_phrase
和match_phrase_prefix
使用,只需要指定type
类型即可:
GET t3/doc/_search
{"query": {"multi_match": {"query": "gi","fields": ["title"],"type": "phrase_prefix"}}
}GET t3/doc/_search
{"query": {"multi_match": {"query": "girl","fields": ["title"],"type": "phrase"}}
}
3. term 查询
3.1 初始 es 的分析器
term
查询用于精确查询,但是不适用于 text
类型的字段查询。
在此之前我们先了解 es
的分析机制,默认的标准分析器会对文档进行:
- 删除大多数的标点符号
- 将文档拆分为单个词条,称为
token
- 将
token
转换为小写
最后保存到倒排序索引上,而倒排序索引用来查询,如 Beautiful girl
经过分析后是这样的:
POST _analyze
{"analyzer": "standard","text": "Beautiful girl"
}# 结果,转换为小写了
{"tokens" : [{"token" : "beautiful","start_offset" : 0,"end_offset" : 9,"type" : "<ALPHANUM>","position" : 0},{"token" : "girl","start_offset" : 10,"end_offset" : 14,"type" : "<ALPHANUM>","position" : 1}]
}
3.2 term 查询
1、准备数据:
# 创建索引,自定义 mapping,后面会讲到
PUT t4
{"mappings": {"doc":{"properties":{"t1":{"type": "text" # 定义字段类型为 text}}}}
}PUT t4/doc/1
{"t1": "Beautiful girl!"
}PUT t4/doc/2
{"t1": "sexy girl!"
}
2、match
查询:
GET t4/doc/_search
{"query": {"match": {"t1": "Beautiful girl!"}}
}
经过分析后,会得到 beautiful、girl
两个 token
,然后再去 t4
索引上去查询,会返回两篇文档:
{"took" : 1,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 2,"max_score" : 0.5753642,"hits" : [{"_index" : "t4","_type" : "doc","_id" : "1","_score" : 0.5753642,"_source" : {"title" : "Beautiful girl"}},{"_index" : "t4","_type" : "doc","_id" : "2","_score" : 0.2876821,"_source" : {"title" : "sex girl"}}]}
}
3、但是我们只想精确查询包含 Beautiful girl
的文档,这时就需要使用 term
来精确查询:
GET t4/doc/_search
{"query": {"term": {"title": "beautiful"}}
}
查询结果:
{"took" : 0,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"skipped" : 0,"failed" : 0},"hits" : {"total" : 1,"max_score" : 0.2876821,"hits" : [{"_index" : "t4","_type" : "doc","_id" : "1","_score" : 0.2876821,"_source" : {"title" : "Beautiful girl"}}]}
}
注意:
term
查询不适用于类型是text
的字段,可以使用match
查询;另外Beautiful
经过分析后变为beautiful
,查询时使用Beautiful
是查询不到的~
3.3 查询多个
精确查询多个字段:
GET t4/doc/_search
{"query": {"terms": {"title": ["beautiful", "sex"]}}
}