仅返回弹性搜索本机查询 Java api 中的特定字段 [英] Only return specific fields in elastic search native query Java api

问题描述

我正在构建本机查询，但我只想返回某些字段，所有这些字段都保存在父字段中.我想我正在寻找与 REST API 的 _source 等效的 QueryBuilders 或 NativeSearchQueryBuilder.这是一个代码示例:

I'm building a native query but I only want to return certain fields, all of which are held within a parent field. I think I am looking for the QueryBuilders or NativeSearchQueryBuilder equivalent of the REST API's _source. Here's a code example:

NativeSearchQueryBuilder sb = new NativeSearchQueryBuilder()
.withIndices("myIndex")
.withTypes("myType")
.withQuery(QueryBuilders.queryStringQuery("parent.field2:Foo*"));
.withFields("parent.field1");

我希望这仅返回与具有 parent.field2 的对象(如 Foo*)相关联的 parent.field1 的列表.但它什么都不返回.

I'd expect this to return a list of only parent.field1 that are associated with objects that have parent.field2 like Foo*. But it returns nothing.

感谢您的帮助！

推荐答案

经过一番研究，我发现答案在 NativeSearchQueryBuilder.我只是使用旧版本的spring-data弹性搜索，所以我看不到这个方法:withSourceFilter.这样做的方法是:

After some research, I found the answer is in NativeSearchQueryBuilder. I was just using an older version of spring-data elastic search, so I could not see this method: withSourceFilter. The way to do this is:

NativeSearchQueryBuilder sb = new NativeSearchQueryBuilder()
.withIndices("myIndex")
.withTypes("myType")
.withQuery(QueryBuilders.queryStringQuery("parent.field2:Foo*"));
.withSourceFilter(new FetchSourceFilter(<String array of includes>, null));

FetchSourceFilter 接受 2 个参数，一个 String[] 包含数组和一个排除数组.在我的示例中，我将像 new String[]{"parent.field1"} 这样的数组传递给 FetchSourceFilter，后者又传递给 withSourceFilter.然后上面的搜索将返回(一旦构建并运行)一个 parent.field1 和 parent.field2 的列表，如 Foo*.

FetchSourceFilter takes 2 arguments, a String[] array of includes and one of excludes. In my example, I'd have an array like new String[]{"parent.field1"} passed to FetchSourceFilter, which in turn is passed to withSourceFilter. The search above will then return (once built and ran) a list of parent.field1 with parent.field2 like Foo*.

我升级到的版本是 spring-data-elasticsearch 2.0.2.

The version I upgraded to was spring-data-elasticsearch 2.0.2.

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