A template for using SQLite in Android

This code is a template for using SQLite in Android to implement a database:

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

public class DatabaseHelper extends SQLiteOpenHelper {

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

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

    // Table Name
    private static final String TABLE_NAME = "table_name";

    // Column names
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_COLUMN_ONE = "column_one";
    private static final String COLUMN_COLUMN_TWO = "column_two";
    private static final String COLUMN_COLUMN_THREE = "column_three";

    // Create table query
    private static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "("
            + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
            + COLUMN_COLUMN_ONE + " TEXT,"
            + COLUMN_COLUMN_TWO + " TEXT,"
            + COLUMN_COLUMN_THREE + " TEXT" + ")";

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

    // Creating the table
    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_TABLE);
    }

    // Upgrading the database
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        // Create tables again
        onCreate(db);
    }

    // Inserting new data into the table
    public long insertData(String columnOne, String columnTwo, String columnThree) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COLUMN_COLUMN_ONE, columnOne);
        contentValues.put(COLUMN_COLUMN_TWO, columnTwo);
        contentValues.put(COLUMN_COLUMN_THREE, columnThree);
        long result = db.insert(TABLE_NAME, null, contentValues);
        db.close();
        return result;
    }

    // Updating existing data in the table
    public int updateData(int id, String columnOne, String columnTwo, String columnThree) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COLUMN_COLUMN_ONE, columnOne);
        contentValues.put(COLUMN_COLUMN_TWO, columnTwo);
        contentValues.put(COLUMN_COLUMN_THREE, columnThree);
        int result = db.update(TABLE

Deleting data from the table:

// Deleting a data from the table
public int deleteData(int id) {
    SQLiteDatabase db = this.getWritableDatabase();
    int result = db.delete(TABLE_NAME, COLUMN_ID + " = ?",
            new String[]{String.valueOf(id)});
    db.close();
    return result;
}

Reading data from the table:

// Reading data from the table
public Cursor readData() {
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NAME, null);
    return cursor;
}

The above code is a template for using SQLite in Android. In this code, we first create a class `DatabaseHelper` which extends the `SQLiteOpenHelper` class. The `SQLiteOpenHelper` class provides the basic functions required to create, update and delete a database.

We first define the database version, name, table name and column names. The `CREATE_TABLE` query is used to create the table in the database. The `onCreate` method is called when the database is first created, and it executes the `CREATE_TABLE` query. The `onUpgrade` method is called when the database version is updated, and it drops the old table and creates a new table with the updated version.

The `insertData` method is used to insert new data into the table, the `updateData` method is used to update existing data in the table, and the `deleteData` method is used to delete data from the table. The `readData` method is used to read data from the table.