Android SQLite Database Tutorial with Examples

What is SQLite?
The contents of this example
The steps for working with SQLite Database
Create a project and design the interface
Java Code

1. What is SQLite?

SQLite is a relational database, open source, it is built on the Android operating system, so you can use it any time, and without any further configuration.

Generally with databases such as Oracle, MySQL, .. you need a Driver libary, and create JDBC connection, however with SQLite it is not necessary.

2. The contents of this example

Assume that you create an application that runs on your Android device, the app records the notes in your day. You need a table structure to store the notes.

Name of the table: Note

Column Name	Data Type	Constraint	Description
Note_Id	int	Primary Key	Primary Key
Note_Title	text		Note title
Note_Content	text		Content

Preview the example:

3. The steps for working with SQLite Database

You need to create a utility class for working with SQLite database, this class should extends from SQLiteOpenHelper class. There are two important methods you need to override it is onCreate() and onUpgrade().

Create MyDatabaseHelper class extends from SQLiteOpenHelper.
After extending your class from SQLiteOpenHelper you need to override two methods onCreate() and onUpgrage()
- onCreate() – These is where you need to write create table statements. This is called when database is created.
- onUpgrade() – This method is called when database is upgraded like modifying the table structure, adding constraints to database etc.,

MyDatabaseHelper.java

public class MyDatabaseHelper extends SQLiteOpenHelper {

// ....

public MyDatabaseHelper(Context context)  {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}


@Override
public void onCreate(SQLiteDatabase db) {
    
    // Script to create table.
    String script = "CREATE TABLE " + TABLE_NOTE + "("
            + COLUMN_NOTE_ID + " INTEGER PRIMARY KEY," + COLUMN_NOTE_TITLE + " TEXT,"
            + COLUMN_NOTE_CONTENT + " TEXT" + ")";
    // Execute script.
    db.execSQL(script);
}


@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    // Drop table
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_NOTE);


    // Recreate
    onCreate(db);
}
// ...
}

4. Create a project and design the interface

Create an "Empty Activity" project named SQLiteDemo to practice this example.

Name: SQLiteDemo
Package name: org.o7planning.sqlitedemo

Create an Empty Activity.

File/New/Activity/Empty Activity

Enter:

Activity Name: AddEditNoteActivity
- (Check Generate Layout File)
Layout: activity_add_edit_note
Package name: org.o7planning.sqlitedemo

activity_main.xml

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    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"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginBottom="16dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

activity_add_edit_note.xml

Set ID, Text for components on the interface:

activity_add_edit_note.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    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"
    tools:context=".AddEditNoteActivity">

    <EditText
        android:id="@+id/editText_note_title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:ems="10"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/editText_note_content"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginBottom="16dp"
        android:ems="10"
        android:inputType="textMultiLine"
        app:layout_constraintBottom_toTopOf="@+id/linearLayout3"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editText_note_title" />

    <LinearLayout
        android:id="@+id/linearLayout3"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginBottom="16dp"
        android:orientation="horizontal"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <Button
            android:id="@+id/button_save"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Save" />

        <Button
            android:id="@+id/button_cancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Cancel" />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

5. Java Code

Note.java

package org.o7planning.sqlitedemo.bean;

import java.io.Serializable;

public class Note implements Serializable {

    private int noteId;
    private String noteTitle;
    private String noteContent;

    public Note()  {

    }

    public Note(String noteTitle, String noteContent) {
        this.noteTitle= noteTitle;
        this.noteContent= noteContent;
    }

    public Note(int noteId, String noteTitle, String noteContent) {
        this.noteId= noteId;
        this.noteTitle= noteTitle;
        this.noteContent= noteContent;
    }

    public int getNoteId() {
        return noteId;
    }

    public void setNoteId(int noteId) {
        this.noteId = noteId;
    }
    public String getNoteTitle() {
        return noteTitle;
    }

    public void setNoteTitle(String noteTitle) {
        this.noteTitle = noteTitle;
    }


    public String getNoteContent() {
        return noteContent;
    }

    public void setNoteContent(String noteContent) {
        this.noteContent = noteContent;
    }


    @Override
    public String toString()  {
        return this.noteTitle;
    }

}

MyDatabaseHelper.java

package org.o7planning.sqlitedemo;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

import org.o7planning.sqlitedemo.bean.Note;

import java.util.ArrayList;
import java.util.List;


public class MyDatabaseHelper extends SQLiteOpenHelper {

    private static final String TAG = "SQLite";

    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "Note_Manager";

    // Table name: Note.
    private static final String TABLE_NOTE = "Note";

    private static final String COLUMN_NOTE_ID ="Note_Id";
    private static final String COLUMN_NOTE_TITLE ="Note_Title";
    private static final String COLUMN_NOTE_CONTENT = "Note_Content";

    public MyDatabaseHelper(Context context)  {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    // Create table
    @Override
    public void onCreate(SQLiteDatabase db) {
        Log.i(TAG, "MyDatabaseHelper.onCreate ... ");
        // Script.
        String script = "CREATE TABLE " + TABLE_NOTE + "("
                + COLUMN_NOTE_ID + " INTEGER PRIMARY KEY," + COLUMN_NOTE_TITLE + " TEXT,"
                + COLUMN_NOTE_CONTENT + " TEXT" + ")";
        // Execute Script.
        db.execSQL(script);
    }


    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        Log.i(TAG, "MyDatabaseHelper.onUpgrade ... ");
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NOTE);

        // Create tables again
        onCreate(db);
    }


    // If Note table has no data
    // default, Insert 2 records.
    public void createDefaultNotesIfNeed()  {
        int count = this.getNotesCount();
        if(count ==0 ) {
            Note note1 = new Note("Firstly see Android ListView",
                    "See Android ListView Example in o7planning.org");
            Note note2 = new Note("Learning Android SQLite",
                    "See Android SQLite Example in o7planning.org");
            this.addNote(note1);
            this.addNote(note2);
        }
    }


    public void addNote(Note note) {
        Log.i(TAG, "MyDatabaseHelper.addNote ... " + note.getNoteTitle());

        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(COLUMN_NOTE_TITLE, note.getNoteTitle());
        values.put(COLUMN_NOTE_CONTENT, note.getNoteContent());

        // Inserting Row
        db.insert(TABLE_NOTE, null, values);

        // Closing database connection
        db.close();
    }


    public Note getNote(int id) {
        Log.i(TAG, "MyDatabaseHelper.getNote ... " + id);

        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(TABLE_NOTE, new String[] { COLUMN_NOTE_ID,
                        COLUMN_NOTE_TITLE, COLUMN_NOTE_CONTENT }, COLUMN_NOTE_ID + "=?",
                new String[] { String.valueOf(id) }, null, null, null, null);
        if (cursor != null)
            cursor.moveToFirst();

        Note note = new Note(Integer.parseInt(cursor.getString(0)),
                cursor.getString(1), cursor.getString(2));
        // return note
        return note;
    }


    public List<Note> getAllNotes() {
        Log.i(TAG, "MyDatabaseHelper.getAllNotes ... " );

        List<Note> noteList = new ArrayList<Note>();
        // Select All Query
        String selectQuery = "SELECT  * FROM " + TABLE_NOTE;

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);

        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Note note = new Note();
                note.setNoteId(Integer.parseInt(cursor.getString(0)));
                note.setNoteTitle(cursor.getString(1));
                note.setNoteContent(cursor.getString(2));
                // Adding note to list
                noteList.add(note);
            } while (cursor.moveToNext());
        }

        // return note list
        return noteList;
    }

    public int getNotesCount() {
        Log.i(TAG, "MyDatabaseHelper.getNotesCount ... " );

        String countQuery = "SELECT  * FROM " + TABLE_NOTE;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);

        int count = cursor.getCount();

        cursor.close();

        // return count
        return count;
    }


    public int updateNote(Note note) {
        Log.i(TAG, "MyDatabaseHelper.updateNote ... "  + note.getNoteTitle());

        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(COLUMN_NOTE_TITLE, note.getNoteTitle());
        values.put(COLUMN_NOTE_CONTENT, note.getNoteContent());

        // updating row
        return db.update(TABLE_NOTE, values, COLUMN_NOTE_ID + " = ?",
                new String[]{String.valueOf(note.getNoteId())});
    }

    public void deleteNote(Note note) {
        Log.i(TAG, "MyDatabaseHelper.updateNote ... " + note.getNoteTitle() );

        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_NOTE, COLUMN_NOTE_ID + " = ?",
                new String[] { String.valueOf(note.getNoteId()) });
        db.close();
    }

}

MainActivity.java

package org.o7planning.sqlitedemo;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import org.o7planning.sqlitedemo.bean.Note;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private static final int MENU_ITEM_VIEW = 111;
    private static final int MENU_ITEM_EDIT = 222;
    private static final int MENU_ITEM_CREATE = 333;
    private static final int MENU_ITEM_DELETE = 444;

    private static final int MY_REQUEST_CODE = 1000;

    private final List<Note> noteList = new ArrayList<Note>();
    private ArrayAdapter<Note> listViewAdapter;

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

        // Get ListView object from xml
        this.listView = (ListView) findViewById(R.id.listView);

        MyDatabaseHelper db = new MyDatabaseHelper(this);
        db.createDefaultNotesIfNeed();

        List<Note> list=  db.getAllNotes();
        this.noteList.addAll(list);


        // Define a new Adapter
        // 1 - Context
        // 2 - Layout for the row
        // 3 - ID of the TextView to which the data is written
        // 4 - the List of data

        this.listViewAdapter = new ArrayAdapter<Note>(this,
                android.R.layout.simple_list_item_1, android.R.id.text1, this.noteList);

        // Assign adapter to ListView
        this.listView.setAdapter(this.listViewAdapter);

        // Register the ListView for Context menu
        registerForContextMenu(this.listView);
    }


    @Override
    public void onCreateContextMenu(ContextMenu menu, View view,
                                    ContextMenu.ContextMenuInfo menuInfo)    {

        super.onCreateContextMenu(menu, view, menuInfo);
        menu.setHeaderTitle("Select The Action");

        // groupId, itemId, order, title
        menu.add(0, MENU_ITEM_VIEW , 0, "View Note");
        menu.add(0, MENU_ITEM_CREATE , 1, "Create Note");
        menu.add(0, MENU_ITEM_EDIT , 2, "Edit Note");
        menu.add(0, MENU_ITEM_DELETE, 4, "Delete Note");
    }

    @Override
    public boolean onContextItemSelected(MenuItem item){
        AdapterView.AdapterContextMenuInfo
                info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();

        final Note selectedNote = (Note) this.listView.getItemAtPosition(info.position);

        if(item.getItemId() == MENU_ITEM_VIEW){
            Toast.makeText(getApplicationContext(),selectedNote.getNoteContent(),Toast.LENGTH_LONG).show();
        }
        else if(item.getItemId() == MENU_ITEM_CREATE){
            Intent intent = new Intent(this, AddEditNoteActivity.class);

            // Start AddEditNoteActivity, (with feedback).
            this.startActivityForResult(intent, MY_REQUEST_CODE);
        }
        else if(item.getItemId() == MENU_ITEM_EDIT ){
            Intent intent = new Intent(this, AddEditNoteActivity.class);
            intent.putExtra("note", selectedNote);

            // Start AddEditNoteActivity, (with feedback).
            this.startActivityForResult(intent,MY_REQUEST_CODE);
        }
        else if(item.getItemId() == MENU_ITEM_DELETE){
            // Ask before deleting.
            new AlertDialog.Builder(this)
                    .setMessage(selectedNote.getNoteTitle()+". Are you sure you want to delete?")
                    .setCancelable(false)
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            deleteNote(selectedNote);
                        }
                    })
                    .setNegativeButton("No", null)
                    .show();
        }
        else {
            return false;
        }
        return true;
    }

    // Delete a record
    private void deleteNote(Note note)  {
        MyDatabaseHelper db = new MyDatabaseHelper(this);
        db.deleteNote(note);
        this.noteList.remove(note);
        // Refresh ListView.
        this.listViewAdapter.notifyDataSetChanged();
    }

    // When AddEditNoteActivity completed, it sends feedback.
    // (If you start it using startActivityForResult ())
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (resultCode == Activity.RESULT_OK && requestCode == MY_REQUEST_CODE) {
            boolean needRefresh = data.getBooleanExtra("needRefresh", true);
            // Refresh ListView
            if (needRefresh) {
                this.noteList.clear();
                MyDatabaseHelper db = new MyDatabaseHelper(this);
                List<Note> list = db.getAllNotes();
                this.noteList.addAll(list);


                // Notify the data change (To refresh the ListView).
                this.listViewAdapter.notifyDataSetChanged();
            }
        }
    }

}

AddEditNoteActivity.java

package org.o7planning.sqlitedemo;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.app.Activity;

import org.o7planning.sqlitedemo.bean.Note;

public class AddEditNoteActivity extends AppCompatActivity {

    private static final int MODE_CREATE = 1;
    private static final int MODE_EDIT = 2;

    private EditText textTitle;
    private EditText textContent;
    private Button buttonSave;
    private Button buttonCancel;

    private Note note;
    private boolean needRefresh;
    private int mode;

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

        this.textTitle = (EditText)this.findViewById(R.id.editText_note_title);
        this.textContent = (EditText)this.findViewById(R.id.editText_note_content);

        this.buttonSave = (Button)findViewById(R.id.button_save);
        this.buttonCancel = (Button)findViewById(R.id.button_cancel);

        this.buttonSave.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v)  {
                 buttonSaveClicked();
            }
        });

        this.buttonCancel.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v)  {
                buttonCancelClicked();
            }
        });

        Intent intent = this.getIntent();
        this.note = (Note) intent.getSerializableExtra("note");
        if(note== null)  {
            this.mode = MODE_CREATE;
        } else  {
            this.mode = MODE_EDIT;
            this.textTitle.setText(note.getNoteTitle());
            this.textContent.setText(note.getNoteContent());
        }
    }

    // User Click on the Save button.
    public void buttonSaveClicked()  {
        MyDatabaseHelper db = new MyDatabaseHelper(this);

        String title = this.textTitle.getText().toString();
        String content = this.textContent.getText().toString();

        if(title.equals("") || content.equals("")) {
            Toast.makeText(getApplicationContext(),
                    "Please enter title & content", Toast.LENGTH_LONG).show();
            return;
        }

        if(mode == MODE_CREATE ) {
            this.note= new Note(title,content);
            db.addNote(note);
        } else  {
            this.note.setNoteTitle(title);
            this.note.setNoteContent(content);
            db.updateNote(note);
        }

        this.needRefresh = true;

        // Back to MainActivity.
        this.onBackPressed();
    }

    // User Click on the Cancel button.
    public void buttonCancelClicked()  {
        // Do nothing, back MainActivity.
        this.onBackPressed();
    }

    // When completed this Activity,
    // Send feedback to the Activity called it.
    @Override
    public void finish() {

        // Create Intent
        Intent data = new Intent();

        // Request MainActivity refresh its ListView (or not).
        data.putExtra("needRefresh", needRefresh);

        // Set Result
        this.setResult(Activity.RESULT_OK, data);
        super.finish();
    }

}

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Android SQLite Database Tutorial with Examples

1. What is SQLite?

2. The contents of this example

3. The steps for working with SQLite Database

4. Create a project and design the interface

5. Java Code

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