it doesn't delete after i called delete method

[shawn peter]

this is my main class

package com.connection.phonedetails;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.widget.Toast;

public class TestDB extends Activity {

	private static final int REQUEST_CODE = 10;
	private static String TYPE = "NONE";
	TelephonyManager telephonyManager;
	DatabaseHandler db;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		// setContentView(R.layout.alert);
		telephonyManager = ((TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE));
		try {
			db = new DatabaseHandler(this);
			SimDetails data = db.getContact(telephonyManager
					.getSimSerialNumber());

			db.deleteContact(data);
			
			SimDetails test = db.getContact(telephonyManager
					.getSimSerialNumber());
			
			

			db.close();
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	
	

}

this is db class

public SimDetails getContact(String id) {

		SimDetails product = new SimDetails();

		try {
			// SimDetails product = new SimDetails();

			String query = "Select * FROM " + TABLE_SIM + " WHERE "
					+ KEY_SIM_NO + " =  \"" + id + "\"";

			SQLiteDatabase db = this.getReadableDatabase();

			/*
			 * String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_SIM + "("
			 * + KEY_NAME + " TEXT," + KEY_SIM_NO + " TEXT PRIMARY KEY," +
			 * KEY_SIM_TYPE + " TEXT" + ")"; db.execSQL(CREATE_CONTACTS_TABLE);
			 */

			// db.execSQL("DROP TABLE IF EXISTS " + TABLE_SIM);

			Cursor cursor = db.rawQuery(query, null);

			if (cursor.moveToFirst()) {

				cursor.moveToFirst();
				product.set_name((cursor.getString(0)));
				product.set_serial_number((cursor.getString(1)));
				product.set_sim_type((cursor.getString(2)));
				cursor.close();
			} else {
				// product.set_name(global);
			}
		} catch (Exception e) {
			product.set_name(global);
			e.printStackTrace();
		}
		return product;
	}

	// Deleting single contact
	public void deleteContact(SimDetails contact) {
		try {
			String query = "Select * FROM " + TABLE_SIM + " WHERE "
					+ KEY_SIM_NO + " =  \"" + contact.get_serial_number()
					+ "\"";

			SQLiteDatabase db = this.getWritableDatabase();
			db.delete(TABLE_SIM,
					KEY_SIM_NO + " = " + contact.get_serial_number(), null);
			db.close();
			

			
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

after i called the delete method in main cactivity also ,record is still in db.The variable test has value as data.please help.

[shawn peter]

I change the delete to below.Then it returns valo 0 from delete.

int s=db.delete(TABLE_SIM,KEY_SIM_NO + " = " + contact.get_serial_number(), null);