Sqlite按用户名发送用户ID

Question

我需要将特定ID发送到另一个活动，“i.putExtra”会发送用户名，但有没有办法发送该用户的ID？

    public void onButtonClick(View v)
{
    if(v.getId() == R.id.Blogin)
    {
        EditText a = (EditText)findViewById(R.id.TFusername);
        String str = a.getText().toString();
        EditText b = (EditText)findViewById(R.id.TFpassword);
        String pass = b.getText().toString();

        String password = helper.searchPass(str);
        if(pass.equals(password))
        {
            Intent i = new Intent(MainActivity.this, Category.class);
            i.putExtra("Username",str);
            startActivity(i);
        }
        else
        {
            Toast warn = Toast.makeText(MainActivity.this , "Username or password wrong!" , Toast.LENGTH_SHORT);
            warn.show();
        } }