请问Android if (pwdDAO.getCount()==0)不执行直接跳到else是什么原因？

package com.szu;

import com.szu.accountsoft.dao.PwdDAO;
 import com.szu.accountsoft.model.Tb_pwd;

import android.app.Activity;
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.Toast;

public class Register_Activity extends Activity {
 private EditText password_1,password_2;
 private Button sure,clear, back;
String password;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.register_activity);



    password_1 = (EditText) findViewById(R.id.password_1);
    password_2 = (EditText) findViewById(R.id.password_2);
    sure = (Button) findViewById(R.id.login_button);
    clear = (Button) findViewById(R.id.clear_Button);
    back = (Button) findViewById(R.id.back);

    setTitle("注册页面");


    sure.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

            if(password_1.getText().toString().trim().equals(""))
            {
                Toast.makeText(Register_Activity.this, "密码不能为空", Toast.LENGTH_LONG).show();
            }
            else if(password_2.getText().toString().trim().equals("") || password_2.getText().toString().trim().equals(""))
            {
                Toast.makeText(Register_Activity.this, "密码不能为空", Toast.LENGTH_LONG).show();
            }
            else if(password_1.getText().length()<6)
            {
                Toast.makeText(Register_Activity.this, "密码长度最少为6", Toast.LENGTH_SHORT).show();
            }
            else if(password_2.getText().length()<6)
            {
                Toast.makeText(Register_Activity.this, "密码长度最少为6", Toast.LENGTH_SHORT).show();
            }
            else if(password_1.getText().toString().trim().equals(password_2.getText().toString().trim()))
            {

                password = password_1.getText().toString().trim();      
            Tb_pwd tb_pwd=new Tb_pwd(password);
              PwdDAO pwdDAO = new PwdDAO(Register_Activity.this);// 创建PwdDAO对象

            if (pwdDAO.getCount()==0)// 判断数据库中是否已经设置了密码
                {
                    pwdDAO.add(tb_pwd);// 添加用户密码
                    // 弹出信息提示
                Intent intent2 = new Intent(Register_Activity.this, MainActivity.class);// 创建Intent对象
                    Toast.makeText(Register_Activity.this, "注册成功！", Toast.LENGTH_SHORT).show();

                startActivity(intent2);
                    finish();

                }
            else 
            {   
            Toast.makeText(Register_Activity.this, "对不起，密码已存在！", Toast.LENGTH_SHORT).show();
            }


            }

            else
            {
                Toast.makeText(Register_Activity.this, "密码不匹配！", Toast.LENGTH_SHORT).show();
            }
        }
    });

    clear.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            password_1.setText("");
            password_2.setText("");
        }
    });

    back.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            finish();
        }
    });
}


}