文章目錄

• 概述
• 官網
• 示例
• • Object datatype
  • • 讓ES自動創建索引，插入一條數據
    • 查看mapping
    • 需求： 被年齡是28歲的黃藥師評論過的博客
    • 查詢結果不對原因分析
  • Nested datatype
  • • 解決object查詢不對的問題
    • 修改mapping，將comments的類型從object設置為nested
    • 寫入數據
    • 查看mapping
    • nested object 存儲形式
    • 再次查詢
    • score_mode
• limits on nested mappings and objects

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概述

繼續跟中華石杉老師學習ES，第58篇

課程地址： https://www.roncoo.com/view/55

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官網

Nested datatype：戳這里

Object datatype：戳這里

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示例

Object datatype

讓ES自動創建索引，插入一條數據

#讓ES自動創建索引，插入一條數據 PUT /website/blogs/1 {"title": "花無缺發表的一篇帖子","content": "我是花無缺，大家要不要考慮一下投資房產和買股票的事情啊。。。","tags": ["投資","理財"],"comments": [{"name": "小魚兒","comment": "什么股票啊？推薦一下唄","age": 28,"stars": 4,"date": "2016-09-01"},{"name": "黃藥師","comment": "我喜歡投資房產，風，險大收益也大","age": 31,"stars": 5,"date": "2016-10-22"}] }

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查看mapping

GET /website/_mapping/blogs/

返回：

{"website": {"mappings": {"blogs": {"properties": {"comments": {"properties": {"age": {"type": "long"},"comment": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}},"date": {"type": "date"},"name": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}},"stars": {"type": "long"}}},"content": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}},"tags": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}},"title": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}}}}}} }

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需求： 被年齡是28歲的黃藥師評論過的博客

#被年齡是28歲的黃藥師評論過的博客 GET /website/blogs/_search {"query": {"bool": {"must": [{"match": {"comments.name": "黃藥師"}},{"match": {"comments.age": 28}}]}} }

返回：

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查詢結果不對原因分析

官方文檔： 戳這里

歸根到底 還是object類型數據結構的底層存儲導致的查詢不正確

{"title": [ "花無缺", "發表", "一篇", "帖子" ],"content": [ "我", "是", "花無缺", "大家", "要不要", "考慮", "一下", "投資", "房產", "買", "股票", "事情" ],"tags": [ "投資", "理財" ],"comments.name": [ "小魚兒", "黃藥師" ],"comments.comment": [ "什么", "股票", "推薦", "我", "喜歡", "投資", "房產", "風險", "收益", "大" ],"comments.age": [ 28, 31 ],"comments.stars": [ 4, 5 ],"comments.date": [ 2016-09-01, 2016-10-22 ] }

object類型底層數據結構，會將一個json數組中的數據，進行扁平化

所以，直接命中了這個document，name=黃藥師，age=28，在范圍之內，正好符合，所以被查詢出來了。

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Nested datatype

解決object查詢不對的問題

引入nested object類型，來解決object類型底層數據結構導致的問題

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修改mapping，將comments的類型從object設置為nested

修改mapping，將comments的類型從object設置為nested

DELETE websitePUT /website {"mappings": {"blogs": {"properties": {"comments": {"type": "nested", "properties": {"name": { "type": "text" },"comment": { "type": "text" },"age": { "type": "short" },"stars": { "type": "short" },"date": { "type": "date" }}}}}} }

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寫入數據

PUT /website/blogs/1 {"title": "花無缺發表的一篇帖子","content": "我是花無缺，大家要不要考慮一下投資房產和買股票的事情啊。。。","tags": [ "投資", "理財" ],"comments": [ {"name": "小魚兒","comment": "什么股票啊？推薦一下唄","age": 28,"stars": 4,"date": "2016-09-01"},{"name": "黃藥師","comment": "我喜歡投資房產，風，險大收益也大","age": 31,"stars": 5,"date": "2016-10-22"}] }

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查看mapping

#查看mapping GET /website/_mapping/blogs/

返回：

{"website": {"mappings": {"blogs": {"properties": {"comments": {"type": "nested","properties": {"age": {"type": "short"},"comment": {"type": "text"},"date": {"type": "date"},"name": {"type": "text"},"stars": {"type": "short"}}},"content": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}},"tags": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}},"title": {"type": "text","fields": {"keyword": {"type": "keyword","ignore_above": 256}}}}}}} }

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nested object 存儲形式

這樣的話，nested object 存儲如下：

{ "comments.name": [ "小魚兒" ],"comments.comment": [ "什么", "股票", "推薦" ],"comments.age": [ 28 ],"comments.stars": [ 4 ],"comments.date": [ 2014-09-01 ] } { "comments.name": [ "黃藥師" ],"comments.comment": [ "我", "喜歡", "投資", "房產", "風險", "收益", "大" ],"comments.age": [ 31 ],"comments.stars": [ 5 ],"comments.date": [ 2014-10-22 ] } { "title": [ "花無缺", "發表", "一篇", "帖子" ],"body": [ "我", "是", "花無缺", "大家", "要不要", "考慮", "一下", "投資", "房產", "買", "股票", "事情" ],"tags": [ "投資", "理財" ] }

再次查詢

GET /website/blogs/_search {"query": {"bool": {"must": [{"match": {"title": "花無缺"}},{"nested": {"path": "comments","query": {"bool": {"must": [{"match": {"comments.name": "黃藥師"}},{"match": {"comments.age": 28}}]}}}}]}} }

改成31的呢

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score_mode

score_mode：max，min，avg，none，默認是avg

如果搜索命中了多個nested document，如何把多個nested document的分數合并為一個分數

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limits on nested mappings and objects

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