What do I need to include in order to use 'Zend_Db_Table_Abstract'?

It is not write in the documentation:
Zend Framework: Documentation

It is in the db section but I include the "Zend/Db.php" and I success to query in it.

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My Hebrew Blog

The Zend Framework is designed on the principle that each class is stored as a separate file, where the filename reflects the classname.
So in order to use Zend_Db_Table_Abstract, you'll need to include the file Zend/Db/Table/Abstract.php, like this:
This also requires that your PHP include_path includes a path to the Zend Framework library. If you haven't included it then read this.

" The Zend Framework is designed on the principle that each class is stored as a separate file, where the filename reflects the classname."

If so I need to create php file for each table class that I use butin the tutorial they use all the table classes in the same script:
Zend Framework: Documentation

Where should I put the tables classes?
I see that there is a models directory in application, for what it use? where do I use it?

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My Hebrew Blog

It's a matter of taste where you put your model files.
Personally I put them in the library, next to the Zend folder.

You can use the handy tool Zend_Loader to load your files dynamically. It's highly recommended!
In your bootstrap file, add the following lines:
Now you can use library classes without require_once, because Zend_Loader includes them for you.

So for example, if you're building a webshop you first create your own namespace in the library folder like this: library/Webshop.

Here's an example of a model:
Save it to your library as a single file: library/Webshop/Products.php.

Now you can use it like this:
...because Zend_Loader automatically looks in the library and includes Webshop/Products.php.

As per the discussion, i hv created the Table Class and saved the table class under library->Tables(new folder)->user.php.

class User extends Zend_Db_Table_Abstract
{
protected $_schema = 'zfwork';// DB name
protected $_name = 'user';// Table name
protected $_primary = 'ID';// primary key setting.
}
Here do i need to give the other fields(email,phone) also? or not required?
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And added the below code to do autoloading of required class.
require_once 'Zend/Loader.php';
Zend_Loader::registerAutoload(); IN the bootstrap file(index.php).
Then the below statment is required for table operation?
"require_once 'Zend/Db/Table/Abstract.php';"

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While using the below code in the controller page (UserController.php) in the listAction() function, i am not getting the output. Can you plz tell me where is the error and whats the problem? Because its confusing.
$table = new Tables_User();
$users = $table->find(2);
print_r($users);

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One more thing is, for DB connection i am using the following code and connected successfully. My question is, if i hv the DB connection then why should i use a separate "Table Classes" like above. And plz tell me the importance of this also.
$options = array('host'=> 'localhost',
'username'=> 'developer',
'password'=> 'success',
'dbname'=> 'test'
);
$db = Zend_Db::factory('Pdo_Mysql', $options);

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Please explain the above DB & Table functionality questions with some example.