Best Practices in PHP

Model - Dao structure  ------>
Check out the below URL  : 
http://www.odi.ch/prog/design/php/guide.php

The DAO should only implement basic select / insert / update operations on one table.


But then,
Q1) what if we have data from different tables ?
Q2) what if i need an array of data ?
Q3) why use try ... catch ...  ?


MVC Pattern ------>
check out below url :
http://anantgarg.com/2009/03/13/write-your-own-php-mvc-framework-part-1/