通过示例在MongoRepository查询中包括Null检查 [英] Include Null check in MongoRepository query by example

问题描述

我正尝试使用以下方法使用MongoRepository从符合某些搜索条件的集合中查找所有内容:

I Am trying to find all from a collection that match certain search criteria using MongoRepository using the following method:

<S extends T> Page<S> findAll(Example<S> example, Pageable pageable);

为此，我将为搜索中包括的所有字段构建一个ExampleMatcher.像这样:

To do this I am building an ExampleMatcher for all fields that are included in the search. like so:

 private ExampleMatcher buildMatcher(FormSearchParameters formSearchParameters) {

    ExampleMatcher exampleMatcher = ExampleMatcher.matching()

            .withIgnorePaths("f1", "f2", "f3", "f4" , "f5");

    if (!StringUtils.isEmpty(formSearchParameters.getName())) {
        exampleMatcher = exampleMatcher.withMatcher("name", match -> match.regex());
    }

    if (!StringUtils.isEmpty(formSearchParameters.getFoo())) {
        exampleMatcher = exampleMatcher.withMatcher("foo", matcher -> matcher.exact().ignoreCase());
    }

    if (null != formSearchParameters.getFilter()) {
        exampleMatcher = exampleMatcher.withMatcher("filter", matcher -> matcher.exact());
    }
    else {
        exampleMatcher = exampleMatcher.withIgnorePaths("filter");
    }

    return exampleMatcher.withIncludeNullValues();
}

但是，我需要添加最后一个检查，其中字段(例如nullField)为null.我似乎无法在文档中找到有关如何进行此操作的任何信息.

However I need to add a last check where a field (say nullField) is null. I cant seem to find any information on how to go about this in the documentation.

我尝试在提供的示例模型中添加以下内容，其中nullField为null，但这似乎被忽略了.

I have tried adding the following where nullField is null in the example model provided but this seems to be ignored.

.withMatcher("nullField", matcher -> matcher.exact())

非常感谢

推荐答案

按照

As per the documentation the Null-handling setting is scoped to the ExampleMatcher (not the property path). So, long story short, you can't.

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