repo_zf1/documentation/manual/en/module_specs/Zend_Db_Table_Definition.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Reviewed: no -->
<sect1 id="zend.db.table.definition">

    <title>Zend_Db_Table_Definition</title>

    <sect2 id="zend.db.table.definition.introduction">

        <title>Introduction</title>

        <para>
            <classname>Zend_Db_Table_Definition</classname> is a class that can be used to
            describe the relationships and configuration options that should be used when
            <classname>Zend_Db_Table</classname> is used via concrete instantiation.
        </para>

    </sect2>

    <sect2 id="zend.db.table.definition.usage">

        <title>Basic Usage</title>

        <para>
            For all of the same options that are available when configuring an extended
            <classname>Zend_Db_Table_Abstract</classname> class, those options are also available when describing
            a definition file. This definition file should be passed to the class at
            instantiation time so that it can know the full definition of all tables
            in said definition.
        </para>

        <para>
            Below is a definition that will describe the table names and relationships
            between table objects. Note: if 'name' is left out of the definition, it
            will be taken as the key of the defined table (an example of this is in the
            'genre' section in the example below.)
        </para>

        <example id="zend.db.table.definition.example1">

            <title>Describing the Definition of a Database Data Model</title>

            <programlisting language="php"><![CDATA[
$definition = new Zend_Db_Table_Definition(array(
    'author' => array(
        'name' => 'author',
        'dependentTables' => array('book')
        ),
    'book' => array(
        'name' => 'book',
        'referenceMap' => array(
            'author' => array(
                'columns' => 'author_id',
                'refTableClass' => 'author',
                'refColumns' => 'id'
                )
            )
        ),
    'genre' => null,
    'book_to_genre' => array(
        'referenceMap' => array(
            'book' => array(
                'columns' => 'book_id',
                'refTableClass' => 'book',
                'refColumns' => 'id'
                ),
            'genre' => array(
                'columns' => 'genre_id',
                'refTableClass' => 'genre',
                'refColumns' => 'id'
                )
            )
        )
    ));
]]></programlisting>

        </example>

        <para>
            As you can see, the same options you'd generally see inside of an
            extended <classname>Zend_Db_Table_Abstract</classname> class are documented in this
            array as well. When passed into <classname>Zend_Db_Table</classname> constructor, this
            definition is <emphasis>persisted</emphasis> to any tables it will need
            to create in order to return the proper rows.
        </para>

        <para>
            Below is an example of the primary table instantiation as well as
            the findDependentRowset() and findManyToManyRowset() calls that will
            correspond to the data model described above:
        </para>

        <example id="zend.db.table.definition.example2">

            <title>Interacting with the described definition</title>

            <programlisting language="php"><![CDATA[
$authorTable = new Zend_Db_Table('author', $definition);
$authors = $authorTable->fetchAll();

foreach ($authors as $author) {
    echo $author->id
       . ': '
       . $author->first_name
       . ' '
       . $author->last_name
       . PHP_EOL;
    $books = $author->findDependentRowset('book');
    foreach ($books as $book) {
        echo '    Book: ' . $book->title . PHP_EOL;
        $genreOutputArray = array();
        $genres = $book->findManyToManyRowset('genre', 'book_to_genre');
        foreach ($genres as $genreRow) {
            $genreOutputArray[] = $genreRow->name;
        }
        echo '        Genre: ' . implode(', ', $genreOutputArray) . PHP_EOL;
    }
}
]]></programlisting>

        </example>

    </sect2>

    <sect2 id="zend.db.table.definition.advanced-usage">

        <title>Advanced Usage</title>

        <para>
            Sometimes you want to use both paradigms for defining and using the
            table gateway: both by extension and concrete instantiation. To do this
            simply leave out any table configurations out of the definition. This will
            allow <classname>Zend_Db_Table</classname> to look for the actual refered class instead of the
            definition key.
        </para>

        <para>
            Building on the example above, we will allow for one of the table configurations
            to be a <classname>Zend_Db_Table_Abstract</classname> extended class, while keeping the rest of the tables
            as part of the definition. We will also show how one would interact with this
            new definition.
        </para>

        <example id="zend.db.table.definition.example3">

            <title>Interacting A Mixed Use Zend_Db_Table Definition</title>

            <programlisting language="php"><![CDATA[
class MyBook extends Zend_Db_Table_Abstract
{
    protected $_name = 'book';
    protected $_referenceMap = array(
        'author' => array(
            'columns' => 'author_id',
            'refTableClass' => 'author',
            'refColumns' => 'id'
            )
        );
}

$definition = new Zend_Db_Table_Definition(array(
    'author' => array(
        'name' => 'author',
        'dependentTables' => array('MyBook')
        ),
    'genre' => null,
    'book_to_genre' => array(
        'referenceMap' => array(
            'book' => array(
                'columns' => 'book_id',
                'refTableClass' => 'MyBook',
                'refColumns' => 'id'
                ),
            'genre' => array(
                'columns' => 'genre_id',
                'refTableClass' => 'genre',
                'refColumns' => 'id'
                )
            )
        )
    ));

$authorTable = new Zend_Db_Table('author', $definition);
$authors = $authorTable->fetchAll();

foreach ($authors as $author) {
    echo $author->id
       . ': '
       . $author->first_name
       . ' '
       . $author->last_name
       . PHP_EOL;
    $books = $author->findDependentRowset(new MyBook());
    foreach ($books as $book) {
        echo '    Book: ' . $book->title . PHP_EOL;
        $genreOutputArray = array();
        $genres = $book->findManyToManyRowset('genre', 'book_to_genre');
        foreach ($genres as $genreRow) {
            $genreOutputArray[] = $genreRow->name;
        }
        echo '        Genre: ' . implode(', ', $genreOutputArray) . PHP_EOL;
    }
}
]]></programlisting>

        </example>

    </sect2>

</sect1>