Android SQLite Database Tutorial

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

  1. Create MyDatabaseHelper class extends from SQLiteOpenHelper.
  2. 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.,
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 SQLiteTutorial to practice this example.
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.sqlitetutorial

activity_main.xml

activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
  android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

  <ListView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:id="@+id/listView"
      android:layout_alignParentTop="true"
      android:layout_alignParentLeft="true"
      android:layout_alignParentStart="true" />
 
</RelativeLayout>

activity_add_edit_note.xml

See SLIDE steps to design the interface:
  • SLIDER:
Interface:
activity_add_edit_note.xml
<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
   android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
   android:paddingRight="@dimen/activity_horizontal_margin"
   android:paddingTop="@dimen/activity_vertical_margin"
   android:paddingBottom="@dimen/activity_vertical_margin"
   tools:context="org.o7planning.sqlitetutorial.AddEditNoteActivity">

   <EditText
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:id="@+id/text_note_title"
       android:layout_row="0"
       android:layout_column="0"
       android:layout_gravity="fill_horizontal"
       android:layout_columnSpan="2" />

   <EditText
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:inputType="textMultiLine"
       android:ems="10"
       android:id="@+id/text_note_content"
       android:layout_row="1"
       android:layout_column="0"
       android:layout_gravity="fill"
       android:layout_columnSpan="2" />

   <Button
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Save"
       android:id="@+id/button_save"
       android:layout_row="2"
       android:layout_column="0"
       android:layout_columnWeight="1"
       android:onClick="buttonSaveClicked" />

   <Button
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Cancel"
       android:id="@+id/button_cancel"
       android:layout_row="2"
       android:layout_column="1"
       android:layout_columnWeight="1"
       android:onClick="buttonCancelClicked" />

</GridLayout>
 

5- Java Code

Note.java
package org.o7planning.sqlitetutorial.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.sqlitetutorial;

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.sqlitetutorial.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.sqlitetutorial;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
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.sqlitetutorial.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
        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) {
        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.sqlitetutorial;

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import org.o7planning.sqlitetutorial.bean.Note;

public class AddEditNoteActivity extends AppCompatActivity {

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

    private int mode;
    private EditText textTitle;
    private EditText textContent;

    private boolean needRefresh;

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

        this.textTitle = (EditText)this.findViewById(R.id.text_note_title);
        this.textContent = (EditText)this.findViewById(R.id.text_note_content);

        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(View view)  {
        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(View view)  {
        // 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();
    }

}

6- Running app

View Slider:
  • SLIDER