java - 为什么我不能在查询 Firestore 中使用 whereEqualTo 条件

Question

我想做的是先检查用户输入的推荐代码是否存在。但问题是，即使我输入的文本不包含在数据库中，它也总是在 addOnSuccessListener 上进行。

//不要介意下一段。我只需要添加更多描述来保存编辑//

我想做的是先检查用户输入的推荐代码是否存在。但问题是，即使我输入的文本不包含在数据库中，它也总是在 addOnSuccessListener 上进行。

我想做的是先检查用户输入的推荐代码是否存在。但问题是，即使我输入的文本不包含在数据库中，它也总是在 addOnSuccessListener 上进行。

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

FirebaseFirestore db = FirebaseFirestore.getInstance();
CollectionReference collectionReference = db.collection("Buyers");
Query usersDataQuery = collectionReference.whereEqualTo("referrals.userReferralCOde", referalCode);
                usersDataQuery.get().addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
                    @Override
                    public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
                        Users users = new Users();
                        String referedByID = users.getBuyerID();

                        loadingBar = KProgressHUD.create(FirstTimeUserActivity.this)
                                .setStyle(KProgressHUD.Style.SPIN_INDETERMINATE)
                                .setLabel("Please wait")
                                .setDetailsLabel("Creating your Account...")
                                .show();
                        //withReferrals(cfn, cln, referedByID, email, status, id);
                        StyleableToast.makeText(FirstTimeUserActivity.this, "Pumasok.", Toast.LENGTH_LONG, R.style.successtoast).show();

                    }
                }).addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        StyleableToast.makeText(FirstTimeUserActivity.this, "Please enter a Valid Referral Code.", Toast.LENGTH_LONG, R.style.errortoast).show();

                    }

public class Users {
    private String BuyerID, Email, FirstName, LastName, ImageUrl, AccountType, CPoints, WalletAccount;
    private double Latitude, Longitude;
    private @ServerTimestamp Date timestamp;
    private ReferralModel Referrals;

    public Users(){

    }

    public Users(String buyerID, String email, String firstName, String lastName, String imageUrl, String accountType, String CPoints, String walletAccount, double latitude, double longitude, Date timestamp, ReferralModel referrals) {
        BuyerID = buyerID;
        Email = email;
        FirstName = firstName;
        LastName = lastName;
        ImageUrl = imageUrl;
        AccountType = accountType;
        this.CPoints = CPoints;
        WalletAccount = walletAccount;
        Latitude = latitude;
        Longitude = longitude;
        this.timestamp = timestamp;
        Referrals = referrals;
    }

  public String getBuyerID() {
        return BuyerID;
    }

    public void setBuyerID(String buyerID) {
        BuyerID = buyerID;
    }

    public String getEmail() {
        return Email;
    }

    public void setEmail(String email) {
        Email = email;
    }

    public String getFirstName() {
        return FirstName;
    }

    public void setFirstName(String firstName) {
        FirstName = firstName;
    }

    public String getLastName() {
        return LastName;
    }

    public void setLastName(String lastName) {
        LastName = lastName;
    }

    public String getImageUrl() {
        return ImageUrl;
    }

    public void setImageUrl(String imageUrl) {
        ImageUrl = imageUrl;
    }

    public String getAccountType() {
        return AccountType;
    }

    public void setAccountType(String accountType) {
        AccountType = accountType;
    }

    public String getCPoints() {
        return CPoints;
    }

    public void setCPoints(String CPoints) {
        this.CPoints = CPoints;
    }

    public String getWalletAccount() {
        return WalletAccount;
    }

    public void setWalletAccount(String walletAccount) {
        WalletAccount = walletAccount;
    }

    public double getLatitude() {
        return Latitude;
    }

    public void setLatitude(double latitude) {
        Latitude = latitude;
    }

    public double getLongitude() {
        return Longitude;
    }

    public void setLongitude(double longitude) {
        Longitude = longitude;
    }

    public Date getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Date timestamp) {
        this.timestamp = timestamp;
    }

    public ReferralModel getReferrals() {
        return Referrals;
    }

    public void setReferrals(ReferralModel referrals) {
        Referrals = referrals;
    }

                });[![enter image description here][1]][1]


  [1]: /image/Jr9Vm.png

Answer 1

除了您的代码 referrals.userReferralCOde 中有错字，因为它应该是 referrals.userReferralCode，您没有得到任何 Users 对象，因为您正在创建一个新对象。您只需使用 addOnCompleteListener 即可看到 QuerySnapshot 对象包含来自数据库的数据。要查看结果，您应该进行迭代，如以下代码行所示:

FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
CollectionReference buyersReference = rootRef.collection("Buyers");
Query usersDataQuery = buyersReference.whereEqualTo("referrals.userReferralCode", "123");
usersDataQuery.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<QuerySnapshot> task) {
        if (task.isSuccessful()) {
            for (QueryDocumentSnapshot document : task.getResult()) {
                String firstName = document.getString("firstName");
                Log.d(TAG, firstName);
            }
        }
    }
});

您的 logcat 中的结果将是所有 userReferralCode 等于 123 的用户。另请注意，您类(class)中的字段不与数据库中的字段对应。为此，请参阅我在以下帖子中的回答:

• Images not loading from URL by Picasso from Firebase Database

因此，如果您想将数据作为 Users 类的对象获取，请使用该答案中的建议。