%--- MainActivity.java package com.example.myapp; import android.app.Activity; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.widget.Toast; public class MainActivity extends Activity { @Override protected void onCreate(Bundle state) { super.onCreate(state); setContentView(R.layout.activity_main); SQLiteDatabase db = new MySQLiteHelper(this).getWritableDatabase(); /*--- LOOK HERE ---*/ // Delete db.delete("comments", "_id=1", null); //db.execSQL("DELETE FROM articles WHERE _id=" + article.getId()); // Get comment try { Cursor cursor = db.rawQuery("SELECT * FROM comments WHERE _id = 1", null); cursor.moveToFirst(); Toast.makeText( getApplicationContext(), cursor.getString(1), Toast.LENGTH_LONG).show(); cursor.close(); } catch (Exception e) { Toast.makeText( getApplicationContext(), "Comment not exists", Toast.LENGTH_LONG).show(); } } } %--- MySQLiteHelper.java package com.example.myapp; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class MySQLiteHelper extends SQLiteOpenHelper { public static final String DB_NAME = "comments.db"; public static final int DB_VERSION = 1; public MySQLiteHelper(Context context) { super(context, DB_NAME, null, DB_VERSION); } @Override public void onCreate(SQLiteDatabase db) { String sql = "CREATE TABLE comments (" + "_id INTEGER PRIMARY KEY AUTOINCREMENT, " + "comment TEXT NOT NULL" + ")"; db.execSQL(sql); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // db.execSQL("DROP TABLE IF EXISTS comments"); // onCreate(db); } }