Android SQLite Tutorial

Example of SQLite Database for android.

AndroidSQLiteTutorialActivity.java

package com.androidhive.androidsqlite;

import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

public class AndroidSQLiteTutorialActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        DatabaseHandler db = new DatabaseHandler(this);

        /**
         * CRUD Operations
         * */
        // Inserting Contacts
        Log.d("Insert: ", "Inserting ..");
        db.addContact(new Contact("Sandy", "9100000000"));
        db.addContact(new Contact("Darshak", "9199999999"));
        db.addContact(new Contact("Keyur", "9522222222"));
        db.addContact(new Contact("Raj", "9533333333"));

        // Reading all contacts
        Log.d("Reading: ", "Reading all contacts..");
        List<Contact> contacts = db.getAllContacts();

        for (Contact cn : contacts) {
            String log = "Id: "+cn.getID()+" ,Name: " + cn.getName() + " ,Phone: " + cn.getPhoneNumber();
                // Writing Contacts to log
        Log.d("Name: ", log);

        }
    }
}

Contact.java

package com.androidhive.androidsqlite;

public class Contact {

//private variables
int _id;
String _name;
String _phone_number;

// Empty constructor
public Contact(){

}
// constructor
public Contact(int id, String name, String _phone_number){
  this._id = id;
  this._name = name;
  this._phone_number = _phone_number;
}

// constructor
public Contact(String name, String _phone_number){
  this._name = name;
  this._phone_number = _phone_number;
}
// getting ID
public int getID(){
  return this._id;
}

// setting id
public void setID(int id){
  this._id = id;
}

// getting name
public String getName(){
  return this._name;
}

// setting name
public void setName(String name){
  this._name = name;
}

// getting phone number
public String getPhoneNumber(){
  return this._phone_number;
}

// setting phone number
public void setPhoneNumber(String phone_number){
  this._phone_number = phone_number;
}
}

DatabaseHandler.java

package com.androidhive.androidsqlite;

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

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

public class DatabaseHandler extends SQLiteOpenHelper {

// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;

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

// Contacts table name
private static final String TABLE_CONTACTS = "contacts";

// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PH_NO = "phone_number";

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

// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
  String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
    + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
    + KEY_PH_NO + " TEXT" + ")";
  db.execSQL(CREATE_CONTACTS_TABLE);
}

// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);

// Create tables again
onCreate(db);
}

/**
* All CRUD(Create, Read, Update, Delete) Operations
*/

// Adding new contact
void addContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();

  ContentValues values = new ContentValues();
  values.put(KEY_NAME, contact.getName()); // Contact Name
  values.put(KEY_PH_NO, contact.getPhoneNumber()); // Contact Phone

  // Inserting Row
  db.insert(TABLE_CONTACTS, null, values);
  db.close(); // Closing database connection
}

// Getting single contact
Contact getContact(int id) {
SQLiteDatabase db = this.getReadableDatabase();

  Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID,
    KEY_NAME, KEY_PH_NO }, KEY_ID + "=?",
    new String[] { String.valueOf(id) }, null, null, null, null);
  if (cursor != null)
   cursor.moveToFirst();

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

// Getting All Contacts
public List<Contact> getAllContacts() {
  List<Contact> contactList = new ArrayList<Contact>();
  // Select All Query
  String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;

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

  // looping through all rows and adding to list
  if (cursor.moveToFirst()) {
   do {
    Contact contact = new Contact();
    contact.setID(Integer.parseInt(cursor.getString(0)));
    contact.setName(cursor.getString(1));
    contact.setPhoneNumber(cursor.getString(2));
    // Adding contact to list
    contactList.add(contact);
   } while (cursor.moveToNext());
  }

// return contact list
return contactList;
}

// Updating single contact
public int updateContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();

  ContentValues values = new ContentValues();
  values.put(KEY_NAME, contact.getName());
  values.put(KEY_PH_NO, contact.getPhoneNumber());

  // updating row
  return db.update(TABLE_CONTACTS, values, KEY_ID + " = ?",
    new String[] { String.valueOf(contact.getID()) });
}

// Deleting single contact
public void deleteContact(Contact contact) {
  SQLiteDatabase db = this.getWritableDatabase();
  db.delete(TABLE_CONTACTS, KEY_ID + " = ?",
    new String[] { String.valueOf(contact.getID()) });
  db.close();
}

// Getting contacts Count
public int getContactsCount() {
  String countQuery = "SELECT * FROM " + TABLE_CONTACTS;
  SQLiteDatabase db = this.getReadableDatabase();
  Cursor cursor = db.rawQuery(countQuery, null);
  cursor.close();

// return count
return cursor.getCount();
}

}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

</LinearLayout>