Login and Register Activity using SQlite Database in Android Studio

The SQlite database as its name suggests, is a lightweight database which is used to store the data locally in your Android mobile devices. One can create a simple login and register app using SQlite which can also work as test bench or platform for launching the app for web servers. 

Let us first create a Database helper class which extends the properties of SQliteOpenHelperClass.

The code snippet for DB Helper class "DBHelper.class" is as follows:

package com.learnandroid.loginsqlite;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;

public class DBHelper extends SQLiteOpenHelper {
    public static final String DBNAME = "Login.db";
    public DBHelper(Context context) {
        super(context, "Login.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase MyDB) {
        MyDB.execSQL("create Table users(username TEXT primary key, password TEXT)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase MyDB, int i, int i1) {
        MyDB.execSQL("drop Table if exists users");
    }

    public Boolean insertData(String username, String password){
        SQLiteDatabase MyDB = this.getWritableDatabase();
        ContentValues contentValues= new ContentValues();
        contentValues.put("username", username);
        contentValues.put("password", password);
        long result = MyDB.insert("users", null, contentValues);
        if(result==-1) return false;
        else
            return true;
    }

    public Boolean checkusername(String username) {
        SQLiteDatabase MyDB = this.getWritableDatabase();
        Cursor cursor = MyDB.rawQuery("Select * from users where username = ?", new String[]{username});
        if (cursor.getCount() > 0)
            return true;
        else
            return false;
    }

    public Boolean checkusernamepassword(String username, String password){
        SQLiteDatabase MyDB = this.getWritableDatabase();
        Cursor cursor = MyDB.rawQuery("Select * from users where username = ? and password = ?", new String[] {username,password});
        if(cursor.getCount()>0)
            return true;
        else
            return false;
    }
}

Let us first create main_activity.xml which serves as the register page. This page will have three edit text boxes, username, password  and retype password. The code snippet for main_activity.xml is as follows.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/username"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="User Name"
        android:layout_marginTop="50dp"/>

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:layout_marginTop="50dp"
        android:layout_below="@+id/username"/>

    <EditText
        android:id="@+id/repassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Retype Password"
        android:layout_marginTop="50dp"
        android:layout_below="@+id/password"/>

    <Button
        android:id="@+id/btnsignup"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Register"
        android:layout_marginTop="50dp"
        android:layout_below="@+id/repassword"/>

    <Button
        android:id="@+id/btnsignin"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Existing user! Go to Sign in page"
        android:layout_marginTop="50dp"
        android:layout_below="@+id/btnsignup"/>
    
</RelativeLayout>

The code snippet for MainActivity.java is as follows.

package com.learnandroid.loginsqlite;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText username, password, repassword;
    Button signup, signin;
    DBHelper DB;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        username = (EditText) findViewById(R.id.username);
        password = (EditText) findViewById(R.id.password);
        repassword = (EditText) findViewById(R.id.repassword);
        signup = (Button) findViewById(R.id.btnsignup);
        signin = (Button) findViewById(R.id.btnsignin);
        DB = new DBHelper(this);

        signup.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String user = username.getText().toString();
                String pass = password.getText().toString();
                String repass = repassword.getText().toString();

                if(user.equals("")||pass.equals("")||repass.equals(""))
                    Toast.makeText(MainActivity.this, "Please enter all the fields", Toast.LENGTH_SHORT).show();
                else{
                    if(pass.equals(repass)){
                        Boolean checkuser = DB.checkusername(user);
                        if(checkuser==false){
                            Boolean insert = DB.insertData(user, pass);
                            if(insert==true){
                                Toast.makeText(MainActivity.this, "Registered successfully", Toast.LENGTH_SHORT).show();
                                Intent intent = new Intent(getApplicationContext(),HomeActivity.class);
                                startActivity(intent);
                            }else{
                                Toast.makeText(MainActivity.this, "Registration failed", Toast.LENGTH_SHORT).show();
                            }
                        }
                        else{
                            Toast.makeText(MainActivity.this, "User already exists! please sign in", Toast.LENGTH_SHORT).show();
                        }
                    }else{
                        Toast.makeText(MainActivity.this, "Passwords not matching", Toast.LENGTH_SHORT).show();
                    }
                } }
        });

        signin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
                startActivity(intent);
            }
        });
    }
}

Now create another activity for Login. The code snippet for activity_login.xml is as follows.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    tools:context=".LoginActivity">

    <EditText
        android:id="@+id/username1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="User Name"
        android:layout_marginTop="50dp"/>

    <EditText
        android:id="@+id/password1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:layout_marginTop="50dp"
        android:layout_below="@+id/username1"/>

    <Button
        android:id="@+id/btnsignin1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Sign in"
        android:layout_marginTop="50dp"
        android:layout_below="@+id/password1"/>
</RelativeLayout>

The code snippet for LoginActivity.java is as follows:

package com.learnandroid.loginsqlite;
import androidx.appcompat.app.AppCompatActivity;

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

public class LoginActivity extends AppCompatActivity {
    EditText username, password;
    Button btnlogin;
    DBHelper DB;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        username = (EditText) findViewById(R.id.username1);
        password = (EditText) findViewById(R.id.password1);
        btnlogin = (Button) findViewById(R.id.btnsignin1);
        DB = new DBHelper(this);

        btnlogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

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

                if(user.equals("")||pass.equals(""))
                    Toast.makeText(LoginActivity.this, "Please enter all the fields", Toast.LENGTH_SHORT).show();
                else{
                    Boolean checkuserpass = DB.checkusernamepassword(user, pass);
                    if(checkuserpass==true){
                        Toast.makeText(LoginActivity.this, "Sign in successfull", Toast.LENGTH_SHORT).show();
                        Intent intent  = new Intent(getApplicationContext(), HomeActivity.class);
                        startActivity(intent);
                    }else{
                        Toast.makeText(LoginActivity.this, "Invalid Credentials", Toast.LENGTH_SHORT).show();
                    }
                }
            }
        });
    }
} 

Create and emprty activity HomeActivity.java and run the program.

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