Android Cloud Firestore文档字段查询

{
  "name": "John Doe",
  "age": 30,
  "email": "john.doe@example.com",
  "is_active": true
}

// 查询所有年龄大于 25 岁的用户
db.collection("users")
  .whereGreaterThan("age", 25)
  .get()
  .addOnCompleteListener(task -> {
      if (task.isSuccessful()) {
          for (QueryDocumentSnapshot document : task.getResult()) {
              Log.d(TAG, document.getId() + " => " + document.getData());
          }
      } else {
          Log.w(TAG, "Error getting documents.", task.getException());
      }
  });

// 查询年龄大于 25 岁且邮箱包含 "example" 的用户
db.collection("users")
  .whereGreaterThan("age", 25)
  .whereContains("email", "example")
  .get()
  .addOnCompleteListener(task -> {
      if (task.isSuccessful()) {
          for (QueryDocumentSnapshot document : task.getResult()) {
              Log.d(TAG, document.getId() + " => " + document.getData());
          }
      } else {
          Log.w(TAG, "Error getting documents.", task.getException());
      }
  });

// 查询所有用户并按年龄升序排序
db.collection("users")
  .orderBy("age")
  .get()
  .addOnCompleteListener(task -> {
      if (task.isSuccessful()) {
          for (QueryDocumentSnapshot document : task.getResult()) {
              Log.d(TAG, document.getId() + " => " + document.getData());
          }
      } else {
          Log.w(TAG, "Error getting documents.", task.getException());
      }
  });