How to check when the user logins for the first time Android Studio SQLite

Question

I have a register Activirty where I can create various users and the username and pasword are saved in the database. When I login it redirects me to an Activity. My need is if it is the first time I login it should load the CreateProfile Activity, and if not it should load the Profile Activity. For now I made it with Toast messages, but it always loads the toast message "normal login".

Here is the DBHelper:

package com.example.sqlite;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

import androidx.annotation.Nullable;

public class DBHelper extends SQLiteOpenHelper {

    private Context context;
    private static final String DATABASE_NAME = "Database.db";
    private static final int DATABASE_VERSION = 1;

    // USERS TABLE
    private static final String TABLE_USERS = "USERS";
    private static final String COLUMN_ID = "user_id";
    private static final String COLUMN_USERNAME = "username";
    private static final String COLUMN_PASSWORD = "password";
    private static final String COLUMN_FIRST_TIME = "first_time";


    // PROFILE TABLE
    private static final String TABLE_PROFILE = "PROFILE";
    //private static final String COLUMN_PROF_ID = "profile_id";
    private static final String COLUMN_FIRSTNAME = "firstname";
    private static final String COLUMN_LASTNAME = "lastname";
    private static final String COLUMN_AGE = "age";
    private static final String COLUMN_WEIGHT = "weight";
    private static final String COLUMN_HEIGHT = "height";
   // private static final String COLUMN_GENDER = "gender";

    public DBHelper(@Nullable Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //String usersQuery = "CREATE TABLE " + TABLE_USERS + " (" + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_USERNAME + " TEXT, " + COLUMN_PASSWORD + " INTEGER " + ")";
        //String profileQuery = "CREATE TABLE " + TABLE_PROFILE + " (" + COLUMN_ID + " INTEGER , " + COLUMN_FIRST_NAME + " TEXT, " + COLUMN_LAST_NAME + " TEXT, " + COLUMN_AGE + " INTEGER, " + COLUMN_WEIGHT + " INTEGER, " + COLUMN_HEIGHT + " INTEGER " + ")";
        String usersQuery  = String.format("CREATE TABLE IF NOT EXISTS %s ( %s INTEGER PRIMARY KEY AUTOINCREMENT, %s TEXT, %s INTEGER, %s INTEGER DEFAULT 1 )",TABLE_USERS,COLUMN_ID,COLUMN_USERNAME,COLUMN_PASSWORD,COLUMN_FIRST_TIME);
        String profileQuery  = String.format("CREATE TABLE IF NOT EXISTS %s ( %s TEXT, %s TEXT, %s INTEGER, %s INTEGER, %s INTEGER)",TABLE_PROFILE,COLUMN_FIRSTNAME,COLUMN_LASTNAME, COLUMN_AGE, COLUMN_WEIGHT, COLUMN_HEIGHT);
        db.execSQL(usersQuery);
        db.execSQL(profileQuery);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int i, int i1) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_USERS);
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_PROFILE);
        onCreate(db);


    }

    public Boolean registerUser(String username, String password){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();

        cv.put(COLUMN_USERNAME, username);
        cv.put(COLUMN_PASSWORD, password);

        long result = db.insert(TABLE_USERS, null, cv);
        db.close();

        if (result != -1)
        {
            Toast.makeText(context, "Registration Successful", Toast.LENGTH_SHORT).show();
            return true;
        }
        else
            return  false;
    }

    Cursor readAllData() {
        String query = "SELECT * FROM " + TABLE_USERS;
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = null;

        if (db != null) {
            cursor = db.rawQuery(query, null);
        }
        return cursor;
    }


    // function that checks if user exists in the database
    public Boolean checkUsername(String username)
    {
        SQLiteDatabase myDB = this.getWritableDatabase();
        Cursor cursor = myDB.rawQuery("select * from users where username = ?", new String[] {username}); // if the data exists the cursor will have some data

        // check if cursor has any data or not
        if (cursor.getCount() > 0)
        {
            return true;  // cursor has some data (user exists)
        }
        else
        {
            return  false;
        }
    }

   public Boolean checkUsernamePassword (String username, String password)  // check the username and password
    {
        SQLiteDatabase myDB = this.getWritableDatabase();
        Cursor cursor = myDB.rawQuery("select * from users where username = ? and password = ?", new String[] {username, password});

        if (cursor.getCount() > 0)  // if the data exists then return true
        {
            return true;
        }
        else
        {
            return false;
        }
    }



    public Boolean insertProfileData(String user_id, String  firstname, String lastname, String age, String weight, String height) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();

        cv.put(COLUMN_ID, user_id);
        cv.put(COLUMN_FIRSTNAME, firstname);
        cv.put(COLUMN_LASTNAME, lastname);
        cv.put(COLUMN_AGE, age);
        cv.put(COLUMN_WEIGHT, weight);
        cv.put(COLUMN_HEIGHT, height);

        int cursor= (int) db.insert(TABLE_PROFILE, null, cv);
        db.close();

        if (cursor > 0)
            return true;
        else
            return false;
    }

    Cursor readProfileInfo() {
        String query = "SELECT * FROM " + TABLE_PROFILE;
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = null;

        if (db != null) {
            cursor = db.rawQuery(query, null);
        }
        return cursor;
    }

    public int fetch_username(String username) {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery("select * from users where username = '"+username +"'" , null);

        if(cursor.moveToFirst()){
            do{
                return cursor.getInt(0);

            }while (cursor.moveToNext());
        }
        else
            return -1;

    }

    public String  fetch_profileData(String id) {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery("select * from PROFILE where user_id = '"+id +"'" , null);
        if(cursor.moveToFirst()){
            do{

                return cursor.getString(1);

            }while (cursor.moveToNext());
        }

        else
            return null;
    }

    

    public boolean check_first_time(String user_id) {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery("select * from users where user_id = '"+user_id +"'" , null);

        if(cursor.moveToFirst()){
            do{
                int value = cursor.getInt(2);
                if(value == 1){
                    return true;
                }
                else{
                    return false;
                }


            }while (cursor.moveToNext());
        }

        else
            return false;
    }

    public boolean update_first_time_status(String user_id) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();

        values.put(COLUMN_FIRST_TIME,0);

        int cursor=   db.update(TABLE_USERS, values, "user_id=?", new String[] {String.valueOf(user_id)});

        db.close();
        if (cursor > 0)
            return true;
        else
            return false;
    }

}

Login Activity:

package com.example.sqlite;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class LoginActivity extends AppCompatActivity {

    TextView signUp;
    EditText username, password;
    Button loginBtn;
    DBHelper myDB;

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

        myDB = new DBHelper(LoginActivity.this);

        signUp = (TextView) findViewById(R.id.tv_signUp);
        username = (EditText) findViewById(R.id.tv_fullname);
        password = (EditText) findViewById(R.id.tv_age);

        loginBtn = (Button) findViewById(R.id.loginBtn);

        signUp.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(LoginActivity.this, RegisterActivity.class));
            }
        });

        loginBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String user = username.getText().toString().trim();
                String pass = password.getText().toString().trim();

                if (user.equals("") || pass.equals(""))
                {
                    Toast.makeText(LoginActivity.this, "Fill all the fields", Toast.LENGTH_SHORT).show();
                }
                else
                {
                    // check username and password if they exist/equal in the database  - if yes login to the app
                    Boolean userPassCheckResult = myDB.checkUsernamePassword(user, pass);
                    if (userPassCheckResult)
                    {
                        int user_id = myDB.fetch_username(user);

                        if(myDB.check_first_time(String.valueOf(user_id)))
                        {
                            Toast.makeText(LoginActivity.this, "! FIRST LOGIN !", Toast.LENGTH_LONG).show();
                            //Intent intent = new Intent(LoginActivity.this, CreateProfileActivity.class);
                            //startActivity(intent);
                            myDB.update_first_time_status(String.valueOf(user_id));
                        }
                        else
                        {
                            Toast.makeText(LoginActivity.this, "normal login..", Toast.LENGTH_LONG).show();
                            //Intent intent = new Intent(LoginActivity.this, ProfileActivity.class);
                            //startActivity(intent);
                        }
                    }
                    else
                    {
                        Toast.makeText(LoginActivity.this, "Invalid Credentials", Toast.LENGTH_SHORT).show();
                    }

                }
            }
        });

    }
}

And in case you need the RegisterActivity:

package com.example.sqlite;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class RegisterActivity extends AppCompatActivity {

    TextView tv_signIn;
    EditText username, password, repeatPass;
    Button registerBtn;
    DBHelper db;

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

        username = findViewById(R.id.username_input);
        password = findViewById(R.id.password_input);
        repeatPass = findViewById(R.id.repeatPass);

        registerBtn = findViewById(R.id.signUpBtn);
        tv_signIn = findViewById(R.id.tv_signIn);

        //DBHelper myDB = new DBHelper(this);

        tv_signIn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);
                startActivity(intent);
            }
        });

        registerBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                DBHelper myDB = new DBHelper(RegisterActivity.this);

                String user = username.getText().toString().trim();
                String pass = password.getText().toString().trim();
                String repass = repeatPass.getText().toString().trim();

                if (user.isEmpty())
                {
                    username.setError("Username is required!");
                    username.requestFocus();
                    return;
                }
                if (pass.isEmpty())
                {
                    password.setError("Password is required!");
                    password.requestFocus();
                    return;
                }

                if (pass.length() < 6)
                {
                    password.setError("Min password length should be 6 characters!");
                    password.requestFocus();
                    return;
                }
                else if (pass.equals(repass))
                {
                    Boolean usercheckResult = myDB.checkUsername(user);
                    if (!usercheckResult) {
                        Boolean checkInsertData = myDB.registerUser(user, pass);    // add user - Register

                        if (checkInsertData) {
                            Toast.makeText(RegisterActivity.this, "Registration Successful", Toast.LENGTH_SHORT).show();
                            Intent intent = new Intent(RegisterActivity.this, com.example.sqlite.LoginActivity.class);
                            startActivity(intent);
                        } else {
                            Toast.makeText(RegisterActivity.this, "Failed", Toast.LENGTH_SHORT).show();
                        }
                    } else {
                        Toast.makeText(RegisterActivity.this, "User already exists. \n Please Sign In", Toast.LENGTH_SHORT).show();
                    }
                } else {
                    Toast.makeText(RegisterActivity.this, "Passwords do not Match!", Toast.LENGTH_SHORT).show();
                    repeatPass.requestFocus();
                    return;
                }


            }

        });
    }
}

Answer 1

You have:-

    Cursor cursor = db.rawQuery("select * from users where user_id = '"+user_id +"'" , null);

    if(cursor.moveToFirst()){
        do{
            int value = cursor.getInt(2);
            if(value == 1){
                return true;
            }
            else{
                return false;
            }
        }while (cursor.moveToNext());
    }

The SQL SELECT * FROM users.... will return as many columns as there are in the users table (4) where getInt(2) will retrieve the 3rd column (the password) is that every likely to be 1 ? (rhetorical)

I believe that you want getInt(3) . However, much better to not hard code offsets and use the getColumnIndex() method to get the column's index by its name.

If search is by user_id, as it's a primary key then it can only return one 1. So you don't need to loop through the cursor.

So you could have:-

public boolean check_first_time(String user_id) {
    SQLiteDatabase db = this.getWritableDatabase();
    boolean rv = false;
    Cursor cursor = db.rawQuery("SELECT * from users where user_id=?" ,new String[]{user_id});
    if(cursor.moveToFirst()){
        rv = cursor.getInt(cursor.getColumnIndex("first_time")) != 1
    }
    cursor.close();
    return rv;
}

• the userid is bound (? is replaced) so SQL injection is eliminated
• you should ALWAYS CLOSE a cursor when done with it.