Zend models and database relationships - php

Question

i'm starting with Zend Framework and I'm a little bit confused with models and relathionships (one-to-many, many-to-many etc).
The "Zend Framework Quick Start" says to create a Zend_Db_Table, a Data Mapper and finally
our model class
Suppose we have a database like this:
table A (
id integer primary key,
name varchar(50)
);
table B (
id integer primary key,
a_id integer references A
);
then, i'll create:
Application_Model_DbTable_A extends Zend_Db_Table_Abstract,
Application_Model_AMapper,
Application_Model_A,
Application_Model_DbTable_B extends Zend_Db_Table_Abstract,
Application_Model_BMapper,
Application_Model_B,
if I understood, i've to store the references informations in
Application_Model_DbTable_A:
protected $_dependentTables = array('B');
and Application_Model_DbTable_B:
protected $_referenceMap = array(
'A' => array(
'columns' => array('a_id'),
'refTableClass' => 'A',
'refColums' => array('id')
)
);
and my models class:
class Application_Model_A
{
protected $_id;
protected $_name;
public function __construct(array $options = null)
{
if(is_array($options)) {
$this->setOptions($options);
}
}
public function __set($name, $value)
{
$method = 'set' . $name;
if (('mapper' == $name) || !method_exists($this, $method)) {
throw new Exception('Invalid property');
}
$this->$method($value);
}
public function __get($name)
{
$method = 'get' . $name;
if (('mapper' == $name) || !method_exists($this, $method)) {
throw new Exception('Invalid property');
}
return $this->$method();
}
public function setOptions(array $options)
{
$methods = get_class_methods($this);
foreach ($options as $key => $value) {
$method = 'set' . ucfirst($key);
if (in_array($method, $methods)) {
$this->$method($value);
}
}
return $this;
}
public function setName($name)
{
$this->_name = (string) $name;
return $this;
}
public function getName()
{
return $this->_name;
}
public function setId($id)
{
$this->_id = (int) $id;
return $this;
}
public function getId()
{
return $this->_id;
}
class Application_Model_B
{
protected $_id;
protected $_a_id;
public function __construct(array $options = null)
{
if(is_array($options)) {
$this->setOptions($options);
}
}
public function __set($name, $value)
{
$method = 'set' . $name;
if (('mapper' == $name) || !method_exists($this, $method)) {
throw new Exception('Invalid property');
}
$this->$method($value);
}
public function __get($name)
{
$method = 'get' . $name;
if (('mapper' == $name) || !method_exists($this, $method)) {
throw new Exception('Invalid property');
}
return $this->$method();
}
public function setOptions(array $options)
{
$methods = get_class_methods($this);
foreach ($options as $key => $value) {
$method = 'set' . ucfirst($key);
if (in_array($method, $methods)) {
$this->$method($value);
}
}
return $this;
}
public function setA_id($a_id)
{
$this->_a_id = (int) $a_id;
return $this;
}
public function getA_id()
{
return $this->_a_id;
}
public function setId($id)
{
$this->_id = (int) $id;
return $this;
}
public function getId()
{
return $this->_id;
}
it's that right?

Answer 1

Well let's assume you have a db table called products. You want to access this table and work with the data.
First you need in models/dbtable/ folder a Product.php file to tell zf where to look for the data:
class Default_Model_DbTable_Product extends Zend_Db_Table_Abstract
{
protected $_name = 'products';
}
So $_name is the name of the db table. Second you need a class where you store all the information like product attributes. Let's say a product has just a name:
class Default_Model_Product{
protected $_name;
public function setName($name) {
$this->_name = $name;
return $this;
}
public function getName() {
return $this->_name;
}
public function __construct(array $options = null) {
if (is_array ( $options )) {
$this->setOptions ( $options );
}
}
//you need the methods below to access an instanz of this class
//put it in every model class
public function __set($name, $value) {
$method = 'set' . $name;
if (('mapper' == $name) || ! method_exists ( $this, $method )) {
throw new Exception ( 'Invalid product property' );
}
$this->$method ( $value );
}
public function __get($name) {
$method = 'get' . $name;
if (('mapper' == $name) || ! method_exists ( $this, $method )) {
throw new Exception ( 'Invalid product property' );
}
return $this->$method ();
}
public function setOptions(array $options) {
$methods = get_class_methods ( $this );
foreach ( $options as $key => $value ) {
$method = 'set' . ucfirst ( $key );
if (in_array ( $method, $methods )) {
$this->$method ( $value );
}
}
return $this;
}
}
Finally you need a mapper class where you actually access the data. You retrieve the data from the table and store it as objects in an array:
class Default_Model_ProductMapper {
protected $_dbTable;
public function setDbTable($dbTable) {
if (is_string ( $dbTable )) {
$dbTable = new $dbTable ();
}
if (! $dbTable instanceof Zend_Db_Table_Abstract) {
throw new Exception ( 'Invalid table data gateway provided' );
}
$this->_dbTable = $dbTable;
return $this;
}
public function getDbTable() {
if (null === $this->_dbTable) {
$this->setDbTable ( 'Default_Model_DbTable_Product' );
}
return $this->_dbTable;
}
//e.g. fetch all
public function fetchAll() {
$resultSet = $this->getDbTable ()->fetchAll ();
$entries = array ();
foreach ( $resultSet as $row ) {
$entry = new Default_Model_Product ();
$entry->setName ( $row->name );
$entries [] = $entry;
}
return $entries;
}
}
This is really straight forward ;)

Answer 2

I really recommend you to use another DB-Framework in your MVC-System.
Zend isn't quite nice with Databases and it's IMO too complicated/ too much code to write.
There are Frameworks which play very nice with Zend (VC) like PHPActiveRecord...
--> http://www.phpactiverecord.org/projects/main/wiki/Frameworks