Elasticsearch学习笔记（四）：ES的搜索方式
大纲：
- query string search
- query DSL
- query filter
- full-text search
- phrase search
- highlight search
- 聚合分析
1. query string search
搜索全部商品：get /ecommerce/product/_search
{
"took": 20,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 1,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 1,
"_source": {
"name": "chaojiban gaolujie yaogao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 1,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
}
]
}
}took：耗费了几毫秒
time_out：是否超时，这里没有
_shards：数据拆成了5个分片，所以对于搜索请求，会打到所有的primary shard（或是它的某个 replica shard也可以）
hits.total：结果数量，这里是三个document。
hits.max_score：score的含义，就是document对于一个search相关度的匹配分数，越相关，就越匹配，分数越高
hits.hits：包含匹配搜索的document数据
query string search的由来，是因为search 参数都是以http请求的query string来附带的。
搜索商品中包含牙膏的数据，按照售价降序排序：get /ecommerce/produce/_search?q=name:yaogao&sort=price:desc
适用于临时在命令行使用的工具，比如curl，快速的发出请求，来检索想要的信息；但是如果查询的条件非常复杂，是很难去构建的，因此，在生产环境当中，是跟少去用的。
{
"took": 3,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": null,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": null,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
},
"sort": [
40
]
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": null,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
},
"sort": [
30
]
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": null,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
},
"sort": [
25
]
}
]
}
}2. query DSL
DSL: domain specified language: 特定领域的语言
http request body,请求体，可以用json来构建复杂的查询语法，比较方便，比query string search强大很多。
查询所有的商品：
get ecommerce/product/_search
{
"query":{
"match_all": {}
}
}查询名称包含yagao的商品，并价格降序
GET /ecommerce/product/_search
{
"query": {
"match": {
"name": "yagao"
}
},
"sort": [
{
"price": {
"order": "desc"
}
}
]
}
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": null,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": null,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
},
"sort": [
40
]
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": null,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
},
"sort": [
30
]
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": null,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
},
"sort": [
25
]
}
]
}
}分页查询商品，假设每页一条，先查询第二页，则应该返回第二条数据
GET /ecommerce/product/_search
{
"query": {
"match_all": {}
},
"from": 1,
"size": 1
}
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 1,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
}
]
}
}只查询指定字段
GET /ecommerce/product/_search
{
"query": {
"match_all": {}
},
"_source": ["name","price"]
}
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 1,
"_source": {
"price": 25,
"name": "jiajieshi yagao"
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 1,
"_source": {
"price": 30,
"name": "chaojiban gaolujie yagao"
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 1,
"_source": {
"price": 40,
"name": "zhonghua yagao"
}
}
]
}
}3. query filter
搜索包含名称，且售价大于26的商品
GET /ecommerce/product/_search
{
"query": {
"bool": {
"must": {
"match": {
"name": "yagao"
}
},
"filter": {
"range": {
"price": {
"gte": 26
}
}
}
}
}
}
{
"took": 16,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 0.5565415,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 0.5565415,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 0.25811607,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
}
]
}
}4. full_text search(全文检索)
GET /ecommerce/product/_search
{
"query": {
"match": {
"producer": "yagao producer"
}
}
}
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 0.25811607,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 0.25811607,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 0.25811607,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 0.16358379,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
}
]
}
}全文检索，首先producer这个字段会首先被es建立倒排索引，如 gaolujie producer会被建立 gaolujie 和producer这样的索引，而查询条件yagao producer也会被拆解为yagao 和producer去搜索。查询出来的结果score分数高的排在前面，表示相关度也越高。
5. phrase search （短语搜索）
与全文检索相对应，相反，全文检索会将输入的搜索串拆解开来，去倒排索引里面一一匹配，只要能匹配任意一个拆解出来的单词，就会作为结果返回，而短语搜索，要求输入的搜索字符串，必须在指定的字段文本中，完全包含一模一样的，才可以算匹配，作为结果返回。
GET /ecommerce/product/_search
{
"query": {
"match_phrase": {
"producer": "zhonghua producer"
}
}
}
{
"took": 121,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.51623213,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 0.51623213,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
}
]
}
}6. highlight search（高亮搜索结果）
GET /ecommerce/product/_search
{
"query" : {
"match" : {
"producer" : "producer"
}
},
"highlight": {
"fields" : {
"producer" : {}
}
}
}
{
"took": 27,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 0.25811607,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 0.25811607,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
},
"highlight": {
"producer": [
"jiajieshi producer"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 0.25811607,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
},
"highlight": {
"producer": [
"zhonghua producer"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 0.16358379,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
},
"highlight": {
"producer": [
"gaolujie producer"
]
}
}
]
}
}7. 聚合分析
（一）计算每个tag（基于之前的数据）下的商品数量
GET /ecommerce/product/_search
{
"aggs": {
"group_by_aggs": {
"terms": {
"field": "tags"
}
}
}
}在直接这样查询的时候，es会报错，原因在于字段aggs的fielddata属性不是为true，只有当为true的情况下才可以取消倒排索引来进行聚合。所以需要设置一下：
PUT /ecommerce/_mapping/product?update_all_types
{
"properties": {
"tags": {
"type": "text",
"fielddata": true
}
}
}设置完了之后查询的结果为
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 1,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 1,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 1,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
}
]
},
"aggregations": {
"group_by_aggs": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2
},
{
"key": "meibai",
"doc_count": 1
},
{
"key": "qingxin",
"doc_count": 1
}
]
}
}
}（二）对名称中包含chaojiban的商品，计算每个tag下的商品数量
GET /ecommerce/product/_search
{
"size": 20,
"query": {
"match": {
"name": "chaojiban"
}
},
"aggs": {
"group_by_aggs": {
"terms": {
"field": "tags"
}
}
}
}
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.5565415,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 0.5565415,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
}
]
},
"aggregations": {
"group_by_aggs": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 1
},
{
"key": "meibai",
"doc_count": 1
}
]
}
}
}size是设置查询结果的最大数量
（三）先按照tags分组，再算每组的平均值，计算每个tag下的商品的平均价格
GET /ecommerce/product/_search
{
"size": 20,
"aggs": {
"group_by_aggs": {
"terms": {
"field": "tags"
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
}
}
{
"took": 12,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 1,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 1,
"_source": {
"name": "chaojiban gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 1,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
}
]
},
"aggregations": {
"group_by_aggs": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2,
"avg_price": {
"value": 27.5
}
},
{
"key": "meibai",
"doc_count": 1,
"avg_price": {
"value": 30
}
},
{
"key": "qingxin",
"doc_count": 1,
"avg_price": {
"value": 40
}
}
]
}
}
}（四）计算每个tag下的商品的平均价格，并且按照平均价格降序排序
GET /ecommerce/product/_search
{
"size": 0,
"aggs": {
"all_tags": {
"terms": {
"field": "tags",
"order": {
"avg_price": "desc"
}
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
}
}
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 0,
"hits": []
},
"aggregations": {
"all_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "qingxin",
"doc_count": 1,
"avg_price": {
"value": 40
}
},
{
"key": "meibai",
"doc_count": 1,
"avg_price": {
"value": 30
}
},
{
"key": "fangzhu",
"doc_count": 2,
"avg_price": {
"value": 27.5
}
}
]
}
}
}（五）按照指定的价格范围区间进行分组，然后在每组内再按照tag进行分组，最后再计算每组的平均价格
GET /ecommerce/product/_search
{
"size": 0,
"aggs": {
"group_by_price": {
"range": {
"field": "price",
"ranges": [
{
"from": 0,
"to": 20
},
{
"from": 20,
"to": 35
},
{
"from":35,
"to": 50
}
]
},
"aggs": {
"group_by_tags": {
"terms": {
"field": "tags"
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
}
}
}
}
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 0,
"hits": []
},
"aggregations": {
"group_by_price": {
"buckets": [
{
"key": "0.0-20.0",
"from": 0,
"to": 20,
"doc_count": 0,
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": []
}
},
{
"key": "20.0-35.0",
"from": 20,
"to": 35,
"doc_count": 2,
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2,
"avg_price": {
"value": 27.5
}
},
{
"key": "meibai",
"doc_count": 1,
"avg_price": {
"value": 30
}
}
]
}
},
{
"key": "35.0-50.0",
"from": 35,
"to": 50,
"doc_count": 1,
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "qingxin",
"doc_count": 1,
"avg_price": {
"value": 40
}
}
]
}
}
]
}
}
}在区间范围的查询过程中，也是基于包左不包右的原则。