简单介绍一下ES的多种搜索方式
1、query string search
格式：
GET /{index}/_searchGET /product/_search
{
"took" : 1,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "product",
"_type" : "_doc",
"_id" : "2",
"_score" : 1.0,
"_source" : {
"name" : "jiajieshi yagao",
"desc" : "youxiao fangzhu",
"price" : 25,
"producer" : "jiajieshi producer",
"tags" : [
"fangzhu"
]
}
},
{
"_index" : "product",
"_type" : "_doc",
"_id" : "3",
"_score" : 1.0,
"_source" : {
"name" : "zhonghua yagao",
"desc" : "caoben zhiwu",
"price" : 40,
"producer" : "zhonghua producer",
"tags" : [
"qingxin"
]
}
}
]
}
}简单见一下查询结果的各个值的含义：
took:耗费的时间 单位是毫秒
timed_out:是否超时
_shards: total是指打到的primary shard(或者replica shard)的个数，successful是指查询成功的分片数，skipped是指跳过的分片个数，failed是指查询失败的分片的个数
hits.total:value代表查询匹配的总数，relation代表The count is accurate (e.g. "eq" means equals).
hits.max_score:是指匹配的文档中相关度分数最高的
hits.hits:包含匹配搜索的document的详细数据
为什么叫做query string search ,主要是因为search参数都是以http请求的query string来附带的
例如搜索商品名称中包含yagao的商品，而且按照售价降序排列：
GET /product/_search?q=name:yagao&sort=price:desc
{
"took" : 36,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : null,
"hits" : [
{
"_index" : "product",
"_type" : "_doc",
"_id" : "3",
"_score" : null,
"_source" : {
"name" : "zhonghua yagao",
"desc" : "caoben zhiwu",
"price" : 40,
"producer" : "zhonghua producer",
"tags" : [
"qingxin"
]
},
"sort" : [
40
]
},
{
"_index" : "product",
"_type" : "_doc",
"_id" : "2",
"_score" : null,
"_source" : {
"name" : "jiajieshi yagao",
"desc" : "youxiao fangzhu",
"price" : 25,
"producer" : "jiajieshi producer",
"tags" : [
"fangzhu"
]
},
"sort" : [
25
]
}
]
}
}query string search适用于临时的在命令行使用的一些工具，比如curl,快速发出请求，来检索想要的信息。但是如果查询请求很复杂，就很难去构建搜索条件，在生产环境中很少使用。
2、query DSL
什么叫做DSL？
DSL：Domain Specified Language 特定领域语言
使用query DSL 查询时查询的参数采用的是请求体（http request body），可以用json的格式来构建查询语法，比较方便，可以构建各种复杂的语法。比query string search 肯定是强大多了
格式：
GET /{index}/{type}/_search
{
"json数据"
}下面都是实际的一些例子：
查询所有的商品:
GET /product/_search
{
"query": {
"match_all": {}
}
}
查询名称中包含yagao的商品，同时按照价格降序排序：
GET /product/_search
{
"query": {
"match": {
"name": "yagao"
}
},
"sort": [
{
"price": {
"order": "desc"
}
}
]
}分页查询商品，总共3个商品，假设每一页就显示1条商品，现在显示第2页，所以就查出来第2个商品
GET /product/_search
{
"query": {
"match_all": {}
},
"from": 1,
"size": 1
}指定要查询出来的商品只返回名称和价格，也就是定制返回字段
GET /product/_search
{
"query": {
"match_all": {}
},
"_source": ["name", "price"]
}query DSL 更加适合生产环境使用，可以构建复杂的查询
3、query filter
搜索商品名称包含yagao，而且售价大于25元的商品
GET /product/_search
{
"query": {
"bool": {
"must": [
{
"match": {
"name": "yagao"
}
}
],
"filter": {
"range": {
"price": {
"gt": 25
}
}
}
}
}
}4、full-text search
GET /product/_search
{
"query": {
"match": {
"producer": "jiajieshi producer"
}
}
}
{
"took" : 0,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : 0.18232156,
"hits" : [
{
"_index" : "product",
"_type" : "_doc",
"_id" : "2",
"_score" : 0.18232156,
"_source" : {
"name" : "jiajieshi yagao",
"desc" : "youxiao fangzhu",
"price" : 25,
"producer" : "jiajieshi producer",
"tags" : [
"fangzhu"
]
}
},
{
"_index" : "product",
"_type" : "_doc",
"_id" : "3",
"_score" : 0.18232156,
"_source" : {
"name" : "zhonghua yagao",
"desc" : "caoben zhiwu",
"price" : 40,
"producer" : "zhonghua producer",
"tags" : [
"qingxin"
]
}
}
]
}
}为什么连zhonghua producer这个文档也被检索出来了，原因是producer这个字段一开始插入数据的时候，就会被拆解，建立倒排索引
jiajieshi 1
zhonghua 2
producer 1,2
搜索yagao producer的时候，会进行拆分变成yagao和producer
5、phrase search短语搜索
phrase search 跟全文检索相反，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去匹配，只要能匹配上任意一个拆解后的单词，就可以作为结果返回。但是phrase search要求输入的搜索串，必须在指定的字段文本中，完全包含一模一样的，才可以算匹配上了，作为结果返回。
GET /product/_search
{
"query": {
"match_phrase": {
"producer": "jiajieshi producer"
}
}
}
{
"took" : 4,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.87546873,
"hits" : [
{
"_index" : "product",
"_type" : "_doc",
"_id" : "2",
"_score" : 0.87546873,
"_source" : {
"name" : "jiajieshi yagao",
"desc" : "youxiao fangzhu",
"price" : 25,
"producer" : "jiajieshi producer",
"tags" : [
"fangzhu"
]
}
}
]
}
}6、highlight search高亮搜索
GET /product/_search
{
"query": {
"match_phrase": {
"producer": "jiajieshi producer"
}
},
"highlight": {
"fields": {
"producer":{}
}
}
}
{
"took" : 23,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.87546873,
"hits" : [
{
"_index" : "product",
"_type" : "_doc",
"_id" : "2",
"_score" : 0.87546873,
"_source" : {
"name" : "jiajieshi yagao",
"desc" : "youxiao fangzhu",
"price" : 25,
"producer" : "jiajieshi producer",
"tags" : [
"fangzhu"
]
},
"highlight" : {
"producer" : [
"jiajieshi producer"
]
}
}
]
}
}