Delete SQLite database data

I'm doing a database program. I would like to have the option of deleting a database from database SQLite . So I did the following:

In my OpenHelper I called the following method:

public void delete (){
    SQLiteDatabase db = getWritableDatabase();
    db.execSQL("DELETE FROM CLIENTE");
    db.close();
}

Where CLIENT is the name of my table. So I created the method:

public void deletar (View view){
    Dados_familiaOpenHelper dados_familiaOpenHelper = new Dados_familiaOpenHelper(null);
    dados_familiaOpenHelper.delete();

}

This method is in a activity that contains a button. This button fires onClick and redirects to this method.

Okay. When I run my program, and I click the button, the app closes. Anyone have any advice or anything that can help me?

@EDIT

My OpenHelper class:

public class Dados_familiaOpenHelper extends SQLiteOpenHelper {

public Dados_familiaOpenHelper(Context context){
    super(context, "Dados_familia", null, 4);
}

@Override
public void onCreate(SQLiteDatabase db) {

    db.execSQL(ScriptDLL.getCreateTableCliente() );

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}
public void delete (){
    SQLiteDatabase db = getWritableDatabase();
    db.execSQL("DELETE FROM CLIENTE");
    db.close();
}