How to use NOT NULL constraints in Android sqlite?

Before getting into example, we should know what sqlite database in android is. SQLite is an opensource SQL database that stores data to a text file on a device. Android comes in with built in SQLite database implementation. SQLite supports all the relational database features. In order to access this database, you don't need to establish any kind of connections for it like JDBC, ODBC etc.

This example demonstrate about How to use NOT NULL constraints in Android sqlite.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = ""
   xmlns:tools = ""
   android:layout_width = "match_parent"
   android:layout_height = "match_parent"
   tools:context = ".MainActivity"
   android:orientation = "vertical">
      android:id = "@+id/name"
      android:layout_width = "match_parent"
      android:hint = "Enter Name"
      android:layout_height = "wrap_content" />
      android:id = "@+id/salary"
      android:layout_width = "match_parent"
      android:inputType = "numberDecimal"
      android:hint = "Enter Salary"
      android:layout_height = "wrap_content" />
      android:id = "@+id/save"
      android:text = "Save"
      android:layout_width = "wrap_content"
      android:layout_height = "wrap_content" />

In the above code, we have taken name and salary as Edit text, when user click on save button it will store the data into sqlite database.

Step 3 − Add the following code to src/

package com.example.andy.myapplication;
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 {
   Button save;
   EditText name, salary;
   protected void onCreate(Bundle readdInstanceState) {
      final DatabaseHelper helper = new DatabaseHelper(this);
      name = findViewById(;
      salary = findViewById(;
      findViewById( View.OnClickListener() {
         public void onClick(View v) {
            if (!name.getText().toString().isEmpty() && !salary.getText().toString().isEmpty()) {
               if (helper.insert(name.getText().toString(), salary.getText().toString())) {
                  Toast.makeText(MainActivity.this, "Inserted", Toast.LENGTH_LONG).show();
               } else {
                  Toast.makeText(MainActivity.this, "NOT Inserted", Toast.LENGTH_LONG).show();
            } else {
               name.setError("Enter NAME");
               salary.setError("Enter Salary");

Step 4 − Add the following code to src/

package com.example.andy.myapplication;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
class DatabaseHelper extends SQLiteOpenHelper {
   public static final String DATABASE_NAME = "MyDBName";
   public static final String CONTACTS_TABLE_NAME = "SalaryDetails";
   public DatabaseHelper(Context context) {
   public void onCreate(SQLiteDatabase db) {
         "create table "+ CONTACTS_TABLE_NAME +"(id integer primary key NOT NULL, name text NOT  NULL,salary text NOT NULL)"
   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
   public boolean insert(String s, String s1) {
      SQLiteDatabase db = this.getWritableDatabase();
      ContentValues contentValues = new ContentValues();
      contentValues.put("name", s);
      contentValues.put("salary", s1);
      db.insert(CONTACTS_TABLE_NAME, null, contentValues);
      return true;

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –

Now enter values as shown below and click on button –

To verify the above result check in android studio as shown below –

Click here to download the project code

Updated on: 30-Jul-2019


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