Elasticsearch幾種查詢語法
1、query string search
2、query DSL
3、query filter
4、full-text search
5、phrase search
6、highlight search
1、query string search
搜尋全部商品：GET /ecommerce/product/_search
took：耗費了幾毫秒
timed_out：是否超時，這裡是沒有
_shards：資料拆成了5個分片，所以對於搜尋請求，會打到所有的primary shard（或者是它的某個replica shard也可以）
hits.total：查詢結果的數量，3個document
hits.max_score：score的含義，就是document對於一個search的相關度的匹配分數，越相關，就越匹配，分數也高
hits.hits：包含了匹配搜尋的document的詳細資料
{
“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”: {
“name”: “jiajieshi yagao”,
“desc”: “youxiao fangzhu”,
“price”: 25,
“producer”: “jiajieshi producer”,
“tags”: [
“fangzhu”
]
}
},
{
“_index”: “ecommerce”,
“_type”: “product”,
“_id”: “1”,
“_score”: 1,
“_source”: {
“name”: “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”
]
}
}
]
}
}
query string search的由來，因為search引數都是以http請求的query string來附帶的
搜尋商品名稱中包含yagao的商品，而且按照售價降序排序：
GET /ecommerce/product/_search?q=name:yagao&sort=price:desc
適用於臨時的在命令列使用一些工具，比如curl，快速的發出請求，來檢索想要的資訊；但是如果查詢請求很複雜，是很難去構建的
在生產環境中，幾乎很少使用query string search
2、query DSL
DSL：Domain Specified Language，特定領域的語言
http request body：請求體，可以用json的格式來構建查詢語法，比較方便，可以構建各種複雜的語法，比query string search肯定強大多了
查詢所有的商品
GET /ecommerce/product/_search
{
"query": { "match_all": {} }
}
查詢名稱包含yagao的商品，同時按照價格降序排序
GET /ecommerce/product/_search
{
"query" : {
"match" : {
"name" : "yagao"
}
},
"sort": [
{ "price": "desc" }
]
}
分頁查詢商品，總共3條商品，假設每頁就顯示1條商品，現在顯示第2頁，所以就查出來第2個商品
GET /ecommerce/product/_search
{
"query": { "match_all": {} },
"from": 1, # 從第1個開始，es從0開始計數的
"size": 100 # 往後查詢100個
}
指定要查詢出來商品的名稱和價格就可以
GET /ecommerce/product/_search
{
"query": { "match_all": {} },
"_source": ["name", "price"]
}
更加適合生產環境的使用，可以構建複雜的查詢
3、query filter
搜尋商品名稱包含yagao，而且售價大於25元的商品
GET /ecommerce/product/_search
{
"query" : {
"bool" : {
"must" : {
"match" : {
"name" : "yagao"
}
},
"filter" : {
"range" : {
"price" : { "gt" : 25 }
}
}
}
}
}
4、full-text search（全文檢索）
GET /ecommerce/product/_search
{
"query" : {
"match" : {
"producer" : "yagao producer"
}
}
}
- producer這個欄位，會先被拆解，建立倒排索引
special 4
yagao 4
producer 1,2,3,4
gaolujie 1
zhognhua 3
jiajieshi 2
- yagao producer —> yagao和producer
{
"took": 4,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0.70293105,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "4",
"_score": 0.70293105,
"_source": {
"name": "special yagao",
"desc": "special meibai",
"price": 50,
"producer": "special yagao producer",
"tags": [
"meibai"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_score": 0.25811607,
"_source": {
"name": "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"
]
}
},
{
"_index": "ecommerce",
"_type": "product",
"_id": "2",
"_score": 0.1805489,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
}
}
]
}
}
5、phrase search（短語搜尋）
跟全文檢索相對應，相反，全文檢索會將輸入的搜尋串拆解開來，去倒排索引裡面去一一匹配，只要能匹配上任意一個拆解後的單詞，就可以作為結果返回
phrase search，要求輸入的搜尋串，必須在指定的欄位文字中，完全包含一模一樣的，才可以算匹配，才能作為結果返回
GET /ecommerce/product/_search
{
"query" : {
"match_phrase" : {
"producer" : "yagao producer"
}
}
}
{
"took": 11,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.70293105,
"hits": [
{
"_index": "ecommerce",
"_type": "product",
"_id": "4",
"_score": 0.70293105,
"_source": {
"name": "special yagao",
"desc": "special meibai",
"price": 50,
"producer": "special yagao producer",
"tags": [
"meibai"
]
}
}
]
}
}
6、highlight search（高亮搜尋結果）
GET /ecommerce/product/_search
{
"query" : {
"match" : {
"producer" : "producer"
}
},
"highlight": {
"fields" : {
"producer" : {}
}
}
}