Android Sqlite Database Tutorial

package com.example.gangsofcoder.testdemo.SqliteDemo;
public class Contact {
    int contactId;
    String contactName, contactPhoneNumber;

    public Contact() {

    }

    public Contact(int id, String name, String number) {
        contactId = id;
        contactPhoneNumber = name;
        contactName = number;
    }

    public Contact(String name, String number) {
        contactName = name;
        contactPhoneNumber = number;
    }

    public int getContactId() {
        return contactId;
    }

    public void setContactId(int contactId) {
        this.contactId = contactId;
    }

    public String getContactName() {
        return contactName;
    }

    public void setContactName(String contactName) {
        this.contactName = contactName;
    }

    public String getContactPhoneNumber() {
        return contactPhoneNumber;
    }

    public void setContactPhoneNumber(String contactPhoneNumber) {
        this.contactPhoneNumber = contactPhoneNumber;
    }


}

2.Database Handler Class for CRUD Operation

package com.example.gangsofcoder.testdemo.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 java.util.ArrayList;
import java.util.List;

public class DatabaseHandler extends SQLiteOpenHelper {
    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "contactDb";
    private static final String TABLE_CONTACT = "contactTable";
    //column name    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_NUMBER = "number";

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

    @Override    public void onCreate(SQLiteDatabase db) {

        String CONTACT_TABLE = "CREATE TABLE " + TABLE_CONTACT + "(" + KEY_ID + " INTEGER PRIMARY KEY," +
                KEY_NAME + " TEXT," + KEY_NUMBER + " TEXT" + ")";
        Log.d("data=", "inside onCreate");
        Log.d("data=", CONTACT_TABLE);
        db.execSQL(CONTACT_TABLE);
    }

    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXIST " + TABLE_CONTACT);
        onCreate(db);
    }

    // Adding new contact    public void addContact(Contact contact) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_NAME, contact.getContactName());
        values.put(KEY_NUMBER, contact.getContactPhoneNumber());
        db.insert(TABLE_CONTACT, null, values);
        db.close();

    }

    // Getting single contact    public Contact getContact(int id) {

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query(TABLE_CONTACT,
                new String[]{KEY_ID, KEY_NAME, KEY_NUMBER},
                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;
    }

    // Getting All Contacts    public List<Contact> getAllContacts() {

        List<Contact> contactList = new ArrayList<>();
        String SELECT_QUERY = "SELECT * FROM " + TABLE_CONTACT;

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(SELECT_QUERY, null);
        Log.d("data=", String.valueOf(cursor));
        if (cursor.moveToFirst()) {
            do {
                Contact contact = new Contact();
                contact.setContactId(Integer.parseInt(cursor.getString(0)));
                contact.setContactName(cursor.getString(1));
                contact.setContactPhoneNumber(cursor.getString(2));
                Log.d("data=", cursor.getString(1));
                contactList.add(contact);
            } while (cursor.moveToNext());
        }
        return contactList;
    }

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

    }

    // Updating single contact    public int updateContact(Contact contact) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_NAME, contact.getContactName());
        values.put(KEY_NUMBER, contact.getContactPhoneNumber());
        return db.update(TABLE_CONTACT, values, KEY_ID + "=?", new String[]{String.valueOf(contact.contactId)});
    }

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

3.Class from where we are calling other two class

package com.example.gangsofcoder.testdemo.SqliteDemo;

import android.content.ContentValues;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

import com.example.gangsofcoder.testdemo.R;

import org.w3c.dom.Text;

import java.util.List;

public class SqliteActivity extends AppCompatActivity {
    TextView tvResult;


    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sqlite_activity);
        tvResult = (TextView) findViewById(R.id.tvResult);

        DatabaseHandler db = new DatabaseHandler(this);
        db.addContact(new Contact("A", "7355173572"));
        db.addContact(new Contact("B", "8699696625"));
        db.addContact(new Contact("C", "1123456854"));
        db.addContact(new Contact("D", "1418529635"));
        db.addContact(new Contact("E", "1234567897"));

        List<Contact> contactList = db.getAllContacts();
        for (Contact cn : contactList) {
            String log = "Id: " + cn.getContactId() + " ,Name: " + cn.getContactName() + " ,Phone: " + cn.getContactPhoneNumber();
            tvResult.setText(log);
        }
    }
}