read All Data From SQLite

i have a database and 6 column in my table . i make database like this class :

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import com.example.persofessional.mybarbershops.OBJ.Obj_Customer;
import java.util.ArrayList;
public class DataBaseCustomerManager extends SQLiteOpenHelper {
    public DataBaseCustomerManager(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
        super(context, "MyBaberShopDB", null, 1);
    }

    SQLiteDatabase db;
    public String Customer_TBL_Query;

    @Override
    public void onCreate(SQLiteDatabase db) {
        Customer_TBL_Query = "CREATE TABLE tbl_Customer ( \n" +
                "    id             INTEGER        PRIMARY KEY\n" +
                "                                  NOT NULL\n" +
                "                                  UNIQUE\n" +
                "                                  DEFAULT ( 101 ),\n" +
                "    CustomerCode   VARCHAR( 11 ),\n" +
                "    CustomerName   VARCHAR( 30 ),\n" +
                "    CustomerAdress VARCHAR( 80 ),\n" +
                "    CustomerTell   VARCHAR( 14 ),\n" +
                "    CustomerMoaref VARCHAR( 15 ) \n" +
                ");\n";

        db.execSQL(Customer_TBL_Query);


    }

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

        db.execSQL("DROP TABLE IF EXISTS tbl_Customer");
        onCreate(db);

    }


    public boolean add_Customer(Obj_Customer objCustomer) {

        boolean result = false;
        try {


            String Add_Customer_Query = "INSERT INTO tbl_Customer (CustomerCode, CustomerName, CustomerAdress,CustomerTell,CustomerMoaref) \n" +
                    "VALUES (" + objCustomer.CustomerCode + ", '" + objCustomer.CustomerName + "', '" + objCustomer.CustomerAdress + "' ,'" + objCustomer.CustomerTell + "','" + objCustomer.CustomerMoaref + "');";

            SQLiteDatabase db = this.getReadableDatabase();
            db.execSQL(Add_Customer_Query);
            db.close();
            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }


    public boolean Update_Customer(Obj_Customer objCustomer) {
        boolean result = false;
        try {


            String Update_Customer_Query = "UPDATE tbl_Customer \n" +
                    "SET CustomerCode=" + objCustomer.CustomerCode + ",CustomerName='" + objCustomer.CustomerName + "',CustomerAdress=" +
                    "'" + objCustomer.CustomerAdress + "' ,CustomerTell='" + objCustomer.CustomerTell + "'," +
                    "CustomerMoaref='" + objCustomer.CustomerMoaref + "';" +
                    "WHERE CustomerTell='" + objCustomer.CustomerTell + "'";

            SQLiteDatabase db = this.getReadableDatabase();
            db.execSQL(Update_Customer_Query);
            db.close();
            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    public Obj_Customer get_Code_Customer(String CustomerCode) {

        Obj_Customer objCustomer = new Obj_Customer();
        try {


            String Search_ByCode_Customer_Query = "SELECT * FROM tbl_Customer WHERE CustomerCode = '" + CustomerCode + "';";
            SQLiteDatabase db = this.getReadableDatabase();
            Cursor cursor = db.rawQuery(Search_ByCode_Customer_Query, null);

            if (cursor.moveToFirst() == true) {
                objCustomer.CustomerCode = cursor.getString(1);
                objCustomer.CustomerName = cursor.getString(2);
                objCustomer.CustomerAdress = cursor.getString(3);
                objCustomer.CustomerTell = cursor.getString(4);
                objCustomer.CustomerMoaref = cursor.getString(5);

            }
        } catch (Exception e) {
            e.printStackTrace();
            objCustomer = null;
        }
        return objCustomer;
    }

    public Obj_Customer get_Tell_Customer(String CustomerTell) {
        Obj_Customer objCustomer = new Obj_Customer();
        try {
            String Search_ByTell_Customer_Query = "SELECT * FROM tbl_Customer WHERE CustomerTell = '" + CustomerTell + "';";
            SQLiteDatabase db = this.getReadableDatabase();
            Cursor cursor = db.rawQuery(Search_ByTell_Customer_Query, null);

            if (cursor.moveToFirst() == true) {
                objCustomer.CustomerCode = cursor.getString(1);
                objCustomer.CustomerName = cursor.getString(2);
                objCustomer.CustomerAdress = cursor.getString(3);
                objCustomer.CustomerTell = cursor.getString(4);
                objCustomer.CustomerMoaref = cursor.getString(5);

            }
        } catch (Exception e) {
            e.printStackTrace();
            objCustomer = null;
        }
        return objCustomer;

    }

    public int getCustomerCount() {
        int result;
        String ShowAllValues = "SELECT * FROM tbl_Customer ;";
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(ShowAllValues, null);
        result = cursor.getCount();
        db.close();
        return result;

    }

    public boolean Del_CustomerByCode(String CustomerCode) {
        boolean result = false;
        try {
            String DeleteCustomerByCode = "DELETE FROM tbl_Customer WHERE CustomerCode='" + CustomerCode + "';";
            SQLiteDatabase db = this.getReadableDatabase();
            db.execSQL(DeleteCustomerByCode);
            db.close();

            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    public boolean Del_CustomerByTell(String CustomerTell) {
        boolean result = false;
        try {
            String DeleteCustomerByTell = "DELETE FROM tbl_Customer WHERE CustomerTell='" + CustomerTell + "';";
            SQLiteDatabase db = this.getReadableDatabase();
            db.execSQL(DeleteCustomerByTell);
            db.close();

            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
}

that's carefully add member and in my MainActivity to show all item in ListView Use this code :

    public void RefreshDisplay() {

        ArrayList<Obj_Customer> Array_objcustomers = new ArrayList<Obj_Customer>();

/*        for (int i = 0; i <= 30; i++) {
            Obj_Customer obj_customers = new Obj_Customer();

            obj_customers.setCustomerName("Test Title ");
            obj_customers.setCustomerTell("Test Desc");

            Array_objcustomers.add(obj_customers);
        }  */


        DataBaseCustomerManager db = new DataBaseCustomerManager(this, null, null, 1);
        Array_objcustomers = db.getAllCustomerItem();

        CustomerArrayeAdapter customerArrayeAdapter = new CustomerArrayeAdapter(getApplicationContext(), Array_objcustomers);

        MyLastCustomerList = (ListView) findViewById(R.id.ListViewMain);
        MyLastCustomerList.setAdapter(customerArrayeAdapter);

    }

But Err !!! where is problem ?!!!