第八章：查詢基礎講解（二） · elasticsearch6.x學習筆記

## **query_string查詢** 例如： ``` POST my_index/_doc/_search { "query":{ "query_string":{ "default_field":"title", "query":"寶馬" } } } ``` 說明： * query_string查詢跟url query查詢類似，就是將查詢條件寫在json體中 * default_field 指的是默認查詢的字段 * query 查詢條件 ‘AND’ 或則 'OR'記的大寫 * fields 指定查詢字段集合，數組形式，例如：['title','author']指查詢title和author字段 ## **Simple Query String Query** * 類似Query String ,但會忽略錯誤的查詢表達式，并且僅支持部分查詢語法 * 其常用的邏輯服務如下，不能使用 AND OR NOT 等關鍵字，否則當普通字符串處理 + 代表AND | 代表OR - 代表NOT ## **query關鍵字** 要搜索的body 例如： ``` GET /_search { "query" : { "term" : { "user" : "kimchy" } } } ``` ## **from / Size** 如果需要分頁，則使用from和size關鍵字。例如： ``` #從0位置開始，獲取10條數據。即獲取：0-10的數據 GET /_search { "from" : 0, "size" : 10, "query" : { "term" : { "user" : "kimchy" } } } ``` ## **sort** 指定結果的排序方式，可以指定某個字段排序，也可用于 _score 按分數排序，以及 _doc 按索引順序排序例如： ``` PUT /my_index { "mappings": { "_doc": { "properties": { "post_date": { "type": "date" }, "user": { "type": "keyword" }, "name": { "type": "keyword" }, "age": { "type": "integer" } } } } } GET /my_index/_search { "sort" : [ { "post_date" : {"order" : "asc"}}, "user", { "name" : "desc" }, { "age" : "desc" }, "_score" ], "query" : { "term" : { "user" : "kimchy" } } } ``` ## **_source** 指定結果返回的字段，默認情況下返回所有字段，也可不返回字段。 ``` #不返回_source字段，即沒有文檔內容返回 POST my_index/_doc/_search { "_source":false, "query":{ "query_string":{ "default_field":"title", "query":"寶馬" } } } #返回結果 { "took": 4, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 2, "max_score": 0.2876821, "hits": [ { "_index": "my_index", "_type": "_doc", "_id": "2", "_score": 0.2876821 }, { "_index": "my_index", "_type": "_doc", "_id": "1", "_score": 0.2876821 } ] } } #返回指定字段開頭的字段 POST my_index/_doc/_search { "_source":"tit*", "query":{ "query_string":{ "default_field":"title", "query":"寶馬" } } } #返回結果 { "took": 2, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 2, "max_score": 0.2876821, "hits": [ { "_index": "my_index", "_type": "_doc", "_id": "2", "_score": 0.2876821, "_source": { "title": "我的寶馬x5有260馬力" } }, { "_index": "my_index", "_type": "_doc", "_id": "1", "_score": 0.2876821, "_source": { "title": "我的寶馬有222馬力" } } ] } } #多個時可以這樣用（返回以"tit"開頭和"na"的字段） POST my_index/_doc/_search { "_source":["tit*","na*"], "query":{ "query_string":{ "default_field":"title", "query":"寶馬" } } } #指定不返回的字段 POST my_index/_doc/_search { "_source":{ "includes":["title"], "excludes":["name"] }, "query":{ "query_string":{ "default_field":"title", "query":"寶馬" } } } ``` ## **highlight** 用于高亮搜索，將搜索出來的結果用標簽包裹起來，不指定標簽默認"``"標簽包裹 ``` POST my_index/_doc/_search { "query":{ "match":{ "title":"寶馬" } }, "highlight":{ "fields":{ "title":{} } } } #返回結果 { "took": 19, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 2, "max_score": 0.2876821, "hits": [ { "_index": "my_index", "_type": "_doc", "_id": "2", "_score": 0.2876821, "_source": { "name": "寶馬", "title": "我的寶馬x5有260馬力" }, "highlight": { "title": [ "我的寶馬x5有260馬力" ] } }, { "_index": "my_index", "_type": "_doc", "_id": "1", "_score": 0.2876821, "_source": { "name": "張三", "title": "我的寶馬有222馬力" }, "highlight": { "title": [ "我的寶馬有222馬力" ] } } ] } } ``` 自定義標簽 ``` POST my_index/_doc/_search { "query":{ "match":{ "title":"寶馬" } }, "highlight":{ "fields":{ "title":{ "pre_tags":[""], "post_tags":[""] } } } } #返回結果 { "took": 6, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 2, "max_score": 0.2876821, "hits": [ { "_index": "my_index", "_type": "_doc", "_id": "2", "_score": 0.2876821, "_source": { "name": "寶馬", "title": "我的寶馬x5有260馬力" }, "highlight": { "title": [ "我的寶馬x5有260馬力" ] } }, { "_index": "my_index", "_type": "_doc", "_id": "1", "_score": 0.2876821, "_source": { "name": "張三", "title": "我的寶馬有222馬力" }, "highlight": { "title": [ "我的寶馬有222馬力" ] } } ] } } ``` 多字段高亮 ``` POST my_index/_doc/_search { "query":{ "match":{ "title":"寶馬" } }, "highlight":{ "require_field_match":false, "fields":{ "title":{ "pre_tags":[""], "post_tags":[""] }, "name":{} } } } #返回結果 { "took": 5, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 2, "max_score": 0.2876821, "hits": [ { "_index": "my_index", "_type": "_doc", "_id": "2", "_score": 0.2876821, "_source": { "name": "寶馬", "title": "我的寶馬x5有260馬力" }, "highlight": { "name": [ "寶馬" ], "title": [ "我的寶馬x5有260馬力" ] } }, { "_index": "my_index", "_type": "_doc", "_id": "1", "_score": 0.2876821, "_source": { "name": "張三", "title": "我的寶馬有222馬力" }, "highlight": { "title": [ "我的寶馬有222馬力" ] } } ] } } ``` 說明：默認情況下只高亮顯示被索引的字段，即：require_filed_match 默認為 true，當 require_filed_match 為 false時，未被索引的字段也可以被高亮顯示。