观看此视频(使用JavaScript，但它确实解决了您的问题):

Take a look at this video (it's in JavaScript, but it exactly solves your problem): https://youtu.be/sKFLI5FOOHs?t=612

基本上，您需要为查询构建数据.在OP示例中，问题将具有类似category_level: "cat_1"的字段.然后，您可以执行查询equalTo("cat_1").如果需要其他查询，则可以省略category和level字段(但是在这种情况下，您将需要处理重复项).

Basically, you need to structure your data for your queries. In OP example Question will have field like category_level: "cat_1". Then you can perform query equalTo("cat_1"). You can leave out both category and level fields if you need it for other queries (but you will need to handle duplication in that case).

如果您知道项目数量很少，最简单的解决方案是仅提取所有category=cat并过滤level=1项目.

If you know that your number of items is small, simplest solution is to just pull all category=cat and filter level=1 items.