上一章节主要介绍了ES的一些重要概念及简单的CRUD，本章内容将重点介绍ES的多种查询方式。ES在使用过程中，查询是最重要的应用场景。
一、Query String Search(‘Query String’方式的搜索)
1.搜索全部商品
GET /shop_index/productInfo/_search
返回结果：
{
"took": 8,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "2",
"_score": 1,
"_source": {
"test": "test"
}
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "zyWpRGkB8mgaHjxk0Hfo",
"_score": 1,
"_source": {
"name": "HuaWei P20",
"desc": "Expen but easy to use",
"price": 5300,
"producer": "HuaWei Producer",
"tags": [
"Expen",
"Fast"
]
}
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "1",
"_score": 1,
"_source": {
"name": "HuaWei Mate8",
"desc": "Cheap and easy to use",
"price": 2500,
"producer": "HuaWei Producer",
"tags": [
"Cheap",
"Fast"
]
}
}
]
}
}字段解释：
took:耗费了几毫秒
timed_out:是否超时，这里是没有
_shards:数据被拆到了5个分片上，搜索时使用了5个分片，5个分片都成功地返回了数据，失败了0个，跳过了0个
hits.total:查询结果的数量，3个document
max_score:就是document对于一个search的相关度的匹配分数，越相关，就越匹配，分数也越高
hits.hits:包含了匹配搜索的document的详细数据2.搜索商品名称中包含HuaWei的商品，而且按照售价降序排序：
下面这种方法也是”Query String Search”的由来，因为search参数都是以http请求的query string来附带的.
GET /shop_index/productInfo/_search?q=name:HuaWei&sort=price:desc返回结果：
{
"took": 23,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": null,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "zyWpRGkB8mgaHjxk0Hfo",
"_score": null,
"_source": {
"name": "HuaWei P20",
"desc": "Expen but easy to use",
"price": 5300,
"producer": "HuaWei Producer",
"tags": [
"Expen",
"Fast"
]
},
"sort": [
5300
]
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "1",
"_score": null,
"_source": {
"name": "HuaWei Mate8",
"desc": "Cheap and easy to use",
"price": 2500,
"producer": "HuaWei Producer",
"tags": [
"Cheap",
"Fast"
]
},
"sort": [
2500
]
}
]
}
}
二、Query DSL(DSL: Domain Specified Language，特定领域的语言)
这种方法是通过一个json格式的http request body请求体作为条件，可以完成多种复杂的查询需求，比query string的功能更加强大
1.搜索所有商品
GET /shop_index/productInfo/_search
{
"query": {
"match_all": {}
}
}返回结果省略…
2.查询名称中包含HuaWei的商品，并且按照价格降序排列
GET /shop_index/productInfo/_search
{
"query": {
"match": {
"name": "HuaWei"
}
},
"sort": [
{
"price": {
"order": "desc"
}
}
]
}返回结果省略…
3.分页查询第二页，每页1条记录
GET /shop_index/productInfo/_search
{
"query": {
"match_all": {}
},
"from": 1,
"size": 1
}返回结果：
{
"took": 6,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "zyWpRGkB8mgaHjxk0Hfo",
"_score": 1,
"_source": {
"name": "HuaWei P20",
"desc": "Expen but easy to use",
"price": 5300,
"producer": "HuaWei Producer",
"tags": [
"Expen",
"Fast"
]
}
}
]
}
}注意：
(1)在实际项目中，如果有条件查询之后再需要分页，不需要单独查询总条数，ES会返回满足条件的总条数，可以直接使用；
(2)ES的分页默认from是从0开始的；
4.只查询特定字段，比如：name，desc和price字段，其他字段不需要返回
GET /shop_index/productInfo/_search
{
"query": {
"match": {
"name": "HuaWei"
}
},
"_source": ["name","desc","price"]
}返回结果：
{
"took": 27,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 0.2876821,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "zyWpRGkB8mgaHjxk0Hfo",
"_score": 0.2876821,
"_source": {
"price": 5300,
"name": "HuaWei P20",
"desc": "Expen but easy to use"
}
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "1",
"_score": 0.2876821,
"_source": {
"price": 2500,
"name": "HuaWei Mate8",
"desc": "Cheap and easy to use"
}
}
]
}
}
三.Query Filter(对查询结果进行过滤)
比如：查询名称中包含HuaWei，并且价格大于4000的商品记录:
GET /shop_index/productInfo/_search
{
"query": {
"bool": {
"must": [
{
"match": {
"name": "HuaWei"
}
}
],
"filter": {
"range": {
"price": {
"gt": 4000
}
}
}
}
}
}返回结果：
{
"took": 195,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.2876821,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "zyWpRGkB8mgaHjxk0Hfo",
"_score": 0.2876821,
"_source": {
"name": "HuaWei P20",
"desc": "Expen but easy to use",
"price": 5300,
"producer": "HuaWei Producer",
"tags": [
"Expen",
"Fast"
]
}
}
]
}
}
四、全文索引(Full-Text Search)
搜索生产厂商字段中包含”HuaWei MateProducer”的商品记录：
GET /shop_index/productInfo/_search
{
"query": {
"match": {
"producer": "HuaWei MateProducer"
}
}
}
返回结果：
{
"took": 8,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0.5753642,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "SiUBRWkB8mgaHjxkJHyS",
"_score": 0.5753642,
"_source": {
"name": "HuaWei Mate10",
"desc": "Cheap and Beauti",
"price": 2300,
"producer": "HuaWei MateProducer",
"tags": [
"Cheap",
"Beauti"
]
}
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "1",
"_score": 0.2876821,
"_source": {
"name": "HuaWei Mate8",
"desc": "Cheap and easy to use",
"price": 2500,
"producer": "HuaWei Producer",
"tags": [
"Cheap",
"Fast"
]
}
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "zyWpRGkB8mgaHjxk0Hfo",
"_score": 0.18232156,
"_source": {
"name": "HuaWei P20",
"desc": "Expen but easy to use",
"price": 5300,
"producer": "HuaWei Producer",
"tags": [
"Expen",
"Fast"
]
}
},
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "CSX8RGkB8mgaHjxkV3w1",
"_score": 0.18232156,
"_source": {
"name": "HuaWei nova 4e",
"desc": "cheap and look nice",
"price": 1999,
"producer": "HuaWei Producer",
"tags": [
"Cheap",
"Nice"
]
}
}
]
}
}从以上结果中可以看到：
id为”SiUBRWkB8mgaHjxkJHyS”的记录score分数最高，表示匹配度最高;
原因：
producer分完词之后包括的词语有：
(1).HuaWei:
匹配到改词的记录ID：’SiUBRWkB8mgaHjxkJHyS’,’1′,’CSX8RGkB8mgaHjxkV3w1′,’zyWpRGkB8mgaHjxk0Hfo’
(2).MateProducer:
匹配到该词的记录ID：’SiUBRWkB8mgaHjxkJHyS’
由于”HuaWei MateProducer”两次匹配到ID为’SiUBRWkB8mgaHjxkJHyS’的记录，所以该记录的score分数最高。
五、Phrase Search(短语搜索)
短语索引和全文索引的区别：
(1)全文匹配：将要搜索的内容分词，然后挨个单词去倒排索引中匹配，只要匹配到任意一个单词，就算是匹配到记录;
(2)短语索引：输入的搜索串，必须在指定的字段内容中，完全包含一模一样的，才可以算匹配，才能作为结果返回;
例如：搜索name中包含”HuaWei MateProducer”短语的商品信息:
GET /shop_index/productInfo/_search
{
"query": {
"match_phrase": {
"producer": "HuaWei MateProducer"
}
}
}返回结果：
{
"took": 158,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.5753642,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "SiUBRWkB8mgaHjxkJHyS",
"_score": 0.5753642,
"_source": {
"name": "HuaWei Mate10",
"desc": "Cheap and Beauti",
"price": 2300,
"producer": "HuaWei MateProducer",
"tags": [
"Cheap",
"Beauti"
]
}
}
]
}
}可以看到只有包含”HuaWei MateProducer”的记录才被返回。
六、Highlight Search(搜索高亮显示)
高亮搜索指的是搜索的结果中，将某些特别需要强调的词使用特定的样式展示出来。
例如：搜索商品名称中包含”Xiao’Mi”的商品，并将搜索的关键词高亮显示：
GET /shop_index/productInfo/_search
{
"query": {
"match": {
"name": "Xiao'Mi"
}
},
"highlight": {
"fields": {
"name": {}
}
}
}返回结果：
{
"took": 348,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.2876821,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "HiX9RGkB8mgaHjxk4nxC",
"_score": 0.2876821,
"_source": {
"name": "Xiao'Mi 9",
"desc": "Expen but nice and Beauti",
"price": 3500,
"producer": "XiaoMi Producer",
"tags": [
"Expen",
"Beauti"
]
},
"highlight": {
"name": [
"<em>Xiao'Mi</em> 9"
]
}
}
]
}
}可以看到，”Xiao’Mi”使用了标签返回了，可以在HTML中直接以斜体展示。
如果想使用自定义高亮样式，可以使用pre_tags和post_tags进行自定义，比如：想使用红色展示，如下所示：
GET /shop_index/productInfo/_search
{
"query": {
"match": {
"name": "Xiao'Mi"
}
},
"highlight": {
"fields": {
"name": {}
},
"pre_tags": [
"<em style='color:red;'>"
],
"post_tags": [
"</em>"
]
}
}返回结果：
{
"took": 10,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.2876821,
"hits": [
{
"_index": "shop_index",
"_type": "productInfo",
"_id": "HiX9RGkB8mgaHjxk4nxC",
"_score": 0.2876821,
"_source": {
"name": "Xiao'Mi 9",
"desc": "Expen but nice and Beauti",
"price": 3500,
"producer": "XiaoMi Producer",
"tags": [
"Expen",
"Beauti"
]
},
"highlight": {
"name": [
"<em style='color:red;'>Xiao'Mi</em> 9"
]
}
}
]
}
}返回结果中的搜索关键字使用表示红色的css样式展示出来。
ES的多种搜索方式到此介绍完毕，每种搜索方式中还包含其他的API，文中没有全部介绍，如果有需要可以自行翻阅官方文档。欢迎评论转发！
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