Question

我正在编写一个Android应用程序，我想检查是否存在字符串（如下面的userCPF和userCRM）以避免重复值。我一直在调查，但看起来我可以添加的只是听众，当我只是想检查一个ID是否存在时。

问题

我该怎么做？

以下是我的ProfileActivity.java和UserInformation（数据库格式）类。

首先，ProfileActivity：

public class ProfileActivity extends AppCompatActivity implements View.OnClickListener {

private FirebaseAuth mAuth;

private TextView textView;
private Button buttonLogout;

private DatabaseReference databaseReference;

private EditText editTextFName, editTextLName, editTextEmail, editTextCPF, editTextCRM;
private Spinner spinnerState;
private Button buttonSave;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_profile);

    mAuth = FirebaseAuth.getInstance();

    //if user is not logged in
    if (mAuth.getCurrentUser() == null) {
        finish();
        startActivity(new Intent(this, MainActivity.class));
    }

    databaseReference = FirebaseDatabase.getInstance().getReference();

    //initializing views
    textView = (TextView) findViewById(R.id.textView);
    editTextFName = (EditText) findViewById(R.id.editTextFName);
    editTextLName = (EditText) findViewById(R.id.editTextLName);
    editTextEmail = (EditText) findViewById(R.id.editTextEmail);
    editTextCPF = (EditText) findViewById(R.id.editTextCPF);
    editTextCRM = (EditText) findViewById(R.id.editTextCRM);
    spinnerState = (Spinner) findViewById(R.id.spinnerState);
    buttonSave = (Button) findViewById(R.id.buttonSave);
    buttonLogout = (Button) findViewById(R.id.buttonLogout);

    FirebaseUser user = mAuth.getCurrentUser();

    textView.setText("Bem Vindo(a) Dr. " + user.getEmail());

    editTextEmail.setText(user.getEmail());

    //adding listener to buttons
    buttonLogout.setOnClickListener(this);
    buttonSave.setOnClickListener(this);
}

private void saveUserInformation() {
    String firstName = editTextFName.getText().toString().trim();
    String lastName = editTextLName.getText().toString().trim();
    String userEmail = editTextEmail.getText().toString();
    String userCPF = editTextCPF.getText().toString().trim();
    String userCRM = editTextCRM.getText().toString().trim();
    String crmState = spinnerState.getSelectedItem().toString();

    //checking if email and passwords are empty
    if(TextUtils.isEmpty(firstName)){
        editTextFName.setError("Por favor, digite seu primeiro nome");
        editTextFName.requestFocus();
        return;
    }

    if(TextUtils.isEmpty(lastName)){
        editTextLName.setError("Por favor, digite seu sobrenome");
        editTextLName.requestFocus();
        return;
    }

    if(TextUtils.isEmpty(userEmail)){
        editTextEmail.setError("Por favor, digite seu e-mail");
        editTextEmail.requestFocus();
        return;
    }

    if(TextUtils.isEmpty(userCPF)){
        editTextCPF.setError("Por favor, digite seu CPF");
        editTextCPF.requestFocus();
        return;
    }

    if(TextUtils.isEmpty(userCRM)){
        editTextCRM.setError("Por favor, digite seu CRM");
        editTextCRM.requestFocus();
        return;
    }

    UserInformation userInformation = new UserInformation(firstName, lastName, userEmail, userCPF, crmState, userCRM);


    FirebaseUser user = mAuth.getCurrentUser();
    databaseReference.child(user.getUid()).setValue(userInformation);
    Toast.makeText(this, "Dados Salvos...", Toast.LENGTH_LONG).show();
    finish();
    startActivity(new Intent(this, BadgeActivity.class));

}




@Override
public void onClick(View view) {
    //if logout button is pressed
    if (view == buttonLogout) {
        mAuth.signOut();
        finish();
        startActivity(new Intent(this, MainActivity.class));
    }

    if (view == buttonSave) {

        saveUserInformation();
    }
}

然后，UserInformation

public class UserInformation {

public String firstName;
public String lastName;
public String userEmail;
public String crmState;
public String userCRM;
public String userCPF;

public UserInformation(){

}

public UserInformation(String firstName, String lastName, String userEmail, String userCPF, String crmState, String userCRM) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.crmState = crmState;
    this.userCRM = userCRM;
    this.userCPF = userCPF;
    this.userEmail = userEmail;
}

Answer 1

试试这个：

DatabaseReference ref=FirebaseDatabase.getInstance().getReference().child("UserInformation");
 ref.orderByChild("userCRM").equalTo(CRM_value_here).addValueEventListener(new ValueEventListener(){
  @Override
public void onDataChange(DataSnapshot dataSnapshot){
 if(dataSnapshot.exists()){
    Toast.makeText(Activity_Name.this, "Stop!",Toast.LENGTH_LONG).show();
      return;
 }
}
   @Override
  public void onCancelled(FirebaseError firebaseError) {

    }
 });

可以执行上述操作，或者如果您使用用户的ID作为密钥，则可以执行此操作：

FirebaseUser currentuser=FirebaseAuth.getInstance().getCurrentUser();

ref.orderByKey().equalTo(currentuser.getUid()).addValueEventListener(new ValueEventListener(){

 //like above

   }

检查整个firebase数据库中是否存在字符串

1 个答案: