Flutter 如何在FiRestore中正确编写OR查询

我正在开发一个匹配的应用程序与Firebase xFlutter .

目标是创建一个函数，从Firestore的userCollection中筛选字段值，以检索符合条件的文档.

这三个论点如下.

• 细绳？MyUid:我的单据ID.
• 细绳？SeltedLanguage:包含指示语言代码的字符串的变量，如‘en’、‘es’等.
• List&lt；string？&gt；meNativeLanguage:包含两个语言代码字符串的变量，如‘en’、‘es’等.

关于QUERIED_LANGUAGE字段，它包含一个字符串，如‘en’、‘es’等.

我执行了下面的代码，但我无法获得任何符合条件的文档ID.控制台上没有错误信息.

static Future<void> getUnmatchedUser(
String? myUid,
List<String?>? selectedLanguage,
List<String?>? meNativeLanguage,
List<String?>? selectedGender,) async{   
  QuerySnapshot<Map<String, dynamic>> querySnapshot = await _userCollection
      .where('matched_status', isEqualTo: false)
      .where('progress_marker', isEqualTo: false)
      .where(FieldPath.documentId, isNotEqualTo: myUid)
      .where("native_language", arrayContains: selectedLanguage![0])      
      .where(Filter.or(
         Filter("queried_language", isEqualTo: meNativeLanguage![0]),
         Filter("queried_language", isEqualTo: meNativeLanguage[1]))) 
      .limit(4) 
      .get();  
}

以下两点已提前排除故障.

• (1)参数变量在运行时不为空.
• (2)当在上述代码中只排除使用OR运算符的WHERE方法的情况下执行该函数时，可以获得与之匹配的文档ID.

基于以上内容，我认为问题出在使用OR查询的WHERE方法部分.

OR查询的使用方法遵循下面的官方指南. https://firebase.google.com/docs/firestore/query-data/queries?_gl=1*lz88cl*_up*MQ..*_ga*MTE2NzA2MjkzOC4xNzA3OTU4MzM0*_ga_CW55HF8NVT*MTcwNzk1ODMzNC4xLjAuMTcwNzk1ODMzNC4wLjAuMA..

请告诉我有什么问题，我将不胜感激.

=========================================================
According to the advice from comments,　I used the hard-coded values to perform a built test like below.

  static Future<String?> getUnmatchedUser(
    String? myUid,
    List<String?>? selectedLanguage,
    List<String?>? meNativeLanguage,
    List<String?>? selectedGender,
    ) async{  
        try { 
          QuerySnapshot<Map<String, dynamic>> querySnapshot = await _userCollection
            .where('matched_status', isEqualTo: false)
            .where('progress_marker', isEqualTo: false)
            .where(FieldPath.documentId, isNotEqualTo: myUid)
            .where("native_language", arrayContains: 'en') 
            .where(Filter.or(
              Filter("queried_language", isEqualTo: 'ja'),
              Filter("queried_language", isEqualTo: 'es'))) 
            .limit(4) 
            .get();  

          print('querySnapshot.docs.length == ${querySnapshot.docs.length}');   

            if (querySnapshot.docs.isEmpty) {return null;}
            if (querySnapshot.docs.isNotEmpty) {
              List<DocumentSnapshot> docs = querySnapshot.docs;
              docs.shuffle();                                    
              DocumentSnapshot docSnapshotFirst = docs[0];
              print("talkuserUid: Document[0] ID: ${docSnapshotFirst.id}");
              return docSnapshotFirst.id;
            }    
              return null;
      } catch (e) {
        print('getUnmatchedUser: ERROR == $e');
        return null;
      }
    }

• 补充:
  • 在if语句中，如果文档是GET，它将对数组进行置乱并返回[0]元素的id(请忽略它们，因为它们在此调试打印中并不相关).

下面是来自FiRestore控制台和VScode控制台的两个文档的屏幕截图，我认为这两个文档符合所有条件，但没有返回.

9lCMFwOVL80Oc9NtXmRu_fields 9lCMFwOVL80Oc9NtXmRu_console u2iftdNbIM0teYtUeen2_fields u2iftdNbIM0teYtUeen2_console

On device with Uid: u2iftdNbIM0teYtUeen2, 'querySnapshot.docs.length == 1' is expected, but it's 0.
(In the screenshots, the reason the process is repeated multiple times is that the function is being executed in a retry function and will be retried until the document succeeds)