Firestore queryBuilder中的多个where查询 [英] multiple where query in firestore queryBuilder

问题描述

我今天才注意到，每当我要查询数据库时，都会收到一个错误，这对我来说实际上没有任何意义，并且查询只是停止工作.几周前就很好了.

I just noticed today that whenever I want to query a database I get an error which doesn't really make a sense to me and querying just stop working. It worked just fine few weeks ago.

无效的查询.不等式(小于，lessThanOrEqual，GreaterThan或GreaterThanOrEqual)必须位于同一领域.但是您在'value1'和'value2'上有不等式过滤器)

Invalid Query. All where filters with an inequality (lessThan, lessThanOrEqual, greaterThan, or greaterThanOrEqual) must be on the same field. But you have inequality filters on 'value1' and 'value2')

  Stream<List<MyModel>> myStream(
      {MyFilter filter, String category}) {
    return _service.collectionsStream(
        path: APIPath.tools(cid, category),
        queryBuilder: filter != null
            ? (query) => query
                .where('value1', isGreaterThan: filter.minValue1)
                .where('value1', isLessThan: filter.maxValue1)
                .where('value2', isLessThan: filter.maxValue2)
                .where('value2', isGreaterThan: filter.minValue2)
            : null,
        builder: (data, documentID) => MyModel.fromMap(data, documentID),
        sort: (lhs, rhs) => lhs.value1.compareTo(rhs.value1));
  }

我做错什么了吗?该错误是什么意思，为什么我上次没有得到它?

Am I doing something wrong? What does that error means and why I didn't get it last time?

推荐答案

Firestore查询只能在服务器上包含关系条件(> ，< 等)单一领域.从查询限制:

A Firestore query can only contain relational conditions (>, <, etc) on a single field. From the documentation on query limitations:

不支持在不同字段上具有范围过滤器的查询.

Queries with range filters on different fields are not supported.

因此，您必须选择要Firestore在其上执行范围过滤的字段.然后，您必须在应用程序代码中执行其他操作.

So you'll have to choose which field you want Firestore to perform a range filter on. You'll then have to do the others in your application code.

要了解有关为何存在此限制的更多信息，并在Firestore的限制范围内实施用例，我强烈建议您观看视频系列

To learn more about why this limit exists, and on working within Firestore's limitations to implement use-cases, I highly recommend checking out the video series Getting to know Cloud Firestore.

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