5.4. Zend_Db_Table
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## 5.4. Zend_Db_Table

### 5.4.1. Introduction

Zend_Db_Table is a TableModule for the Zend Framework. It connects to your database via Zend_Db_Adapter, examines a table for its schema, then aids you in manipulating and fetching rows from that table.

### 5.4.2. Getting Started

The first thing to do is feed the abstract Zend_Db_Table class a default database adapter; unless you specify otherwise, all Zend_Db_Table instances will use this default adapter.

    <?php
    // set up an adapter
    require_once 'Zend/Db.php';
    $params = array (
        'host'     => '127.0.0.1',
        'username' => 'malory',
        'password' => '******',
        'dbname'   => 'camelot'
    );

    $db = Zend_Db::factory('PDO_MYSQL', $params);

    // set the default adapter for all Zend_Db_Table objects
    require_once 'Zend/Db/Table.php';
    Zend_Db_Table::setDefaultAdapter($db);
    ?>

Next, let's assume that you have a table in your database called "round_table". To use Zend_Db_Table with that database table, simply extend Zend_Db_Table to create a new class called RoundTable (note how we "camelize" the round_table name). Then we can examine, manipulate rows, and fetch results from the 'round_table' table in the database via that class.

    <?php
    class RoundTable extends Zend_Db_Table {}
    $table = new RoundTable();
    ?>

### 5.4.3. Table Name and Primary Key

By default, Zend_Db_Table expects that the table name in the database will be the same as its own class name (when converted from CamelCaps to underscore_words). Thus, a Zend_Db_Table class called SomeTableName maps to an SQL table called 'some_table_name'. If you want your class to map to something other than the underscore form of the class name, override the $_name property when defining your class.

    <?php
    class ClassName extends Zend_Db_Table
    {
        // default table name is 'class_name'
        // but we want to map to something else
        protected $_name = 'another_table_name';
    }
    ?>

By default, Zend_Db_Table expects your table to have a primary key named 'id'. (It is better if this column is auto-incremented, but is not required.) If your primary key is named something other than 'id', you can override the $_primary property when defining your class.

    <?php
    class ClassName extends Zend_Db_Table
    {
        // default primary key is 'id'
        // but we want to use something else
        protected $_primary = 'another_column_name';
    }
    ?>

Alternatively, you may set these in the _setup() method of your extended class; just be sure to call the parent::_setup() when you are done.

    <?php
    class ClassName extends Zend_Db_Table
    {
        protected function _setup()
        {
            $this->_name = 'another_table_name';
            $this->_primary = 'another_column_name';
            parent::_setup();
        }
    }
    ?>

### 5.4.4. Inserting Rows

To insert a new row into your table, simply call insert() with an associative array of column:value data. The data will be quoted for you automatically, and the last insert ID will be returned. (Note that this differs from Zend_Db_Adapter::insert(), where the number of rows affected will be returned.)

    <?php
    //
    // INSERT INTO round_table
    //     (noble_title, first_name, favorite_color)
    //     VALUES ("King", "Arthur", "blue")
    //

    class RoundTable extends Zend_Db_Table {}

    $table = new RoundTable();

    $data = array(
        'noble_title' => 'King',
        'first_name'  => 'Arthur',
        'favorite_color' => 'blue',
    )

    $id = $table->insert($data);
    ?>

### 5.4.5. Updating Rows

To update any number of rows in your table, call update() with an associative array of column:value data to set, along with a WHERE clause to determine which rows will be updated. It will update the table and return the number of rows affected.

The data to be set will be quoted for you automatically, but the WHERE clause will not, so you need to quote that yourself with the table's Zend_Db_Adapter object.

    <?php
    //
    // UPDATE round_table
    //     SET favorite_color = "yellow"
    //     WHERE first_name = "Robin"
    //

    class RoundTable extends Zend_Db_Table {}

    $table = new RoundTable();
    $db = $table->getAdapter();

    $set = array(
        'favorite_color' => 'yellow',
    )

    $where = $db->quoteInto('first_name = ?', 'Robin');

    $rows_affected = $table->update($set, $where);
    ?>

### 5.4.6. Deleting Rows

To delete any number of rows in your table, call delete() with a WHERE clause to determine which rows will be deleted. It will then return the number of rows deleted.

The WHERE clause will not be quoted for you, so you need to quote that yourself with the table's Zend_Db_Adapter object.

    <?php
    //
    // DELETE FROM round_table
    //     WHERE first_name = "Patsy"
    //

    class RoundTable extends Zend_Db_Table {}

    $table = new RoundTable();
    $db = $table->getAdapter();

    $where = $db->quoteInto('first_name = ?', 'Patsy');

    $rows_affected = $table->delete($where);
    ?>

### 5.4.7. Finding Rows by Primary Key

As a convienience, you can easily retrieve rows from the table using primary key values with the find() method. This method returns a Zend_Db_Table_Row object if you attempt to find() only one key, or a Zend_Db_Table_Rowset object if you attempt to find() multiple keys.

    <?php
    class RoundTable extends Zend_Db_Table {}

    $table = new RoundTable();

    // SELECT * FROM round_table WHERE id = "1"
    $row = $table->find(1);

    // SELECT * FROM round_table WHERE id IN("1", "2", 3")
    $rowset = $table->find(array(1, 2, 3));
    ?>

### 5.4.8. Fetching One Row

While you can easily find() a row by its primary key, often you will need to add various conditions when retrieving a row. Zend_Db_Table provides fetchRow() for just this purpose. Call fetchRow() with a WHERE clause (and an optional ORDER clause), and Zend_Db_Table will return a Zend_Db_Table_Row that with the first record that matches your conditions.

Note that your WHERE clause will not be quoted for you, so you will need to quote it yourself with the table's Zend_Db_Adapter.

    <?php
    //
    // SELECT * FROM round_table
    //     WHERE noble_title = "Sir"
    //     AND first_name = "Robin"
    //     ORDER BY favorite_color
    //

    class RoundTable extends Zend_Db_Table {}

    $table = new RoundTable();
    $db = $table->getAdapter();

    $where = $db->quoteInto('noble_title = ?', 'Sir')
           . $db->quoteInto('AND first_name = ?', 'Robin');

    $order = 'favorite_color';

    $row = $table->fetchRow($where, $order);
    ?>

### 5.4.9. Fetching Multiple Rows

If you need to retrieve many rows at once, use the fetchAll() method. As with fetchRow(), it takes a WHERE and ORDER clause, but also takes limit-count and limit-offset values to restrict the number of rows returned. It will return a Zend_Db_Table_Rowset object with the selected records.

Note that your WHERE clause will not be quoted for you, so you will need to quote it yourself with the table's Zend_Db_Adapter.

    <?php
    class RoundTable extends Zend_Db_Table {}

    $table = new RoundTable();
    $db = $table->getAdapter();

    // SELECT * FROM round_table
    //     WHERE noble_title = "Sir"
    //     ORDER BY first_name
    //     LIMIT 10 OFFSET 20

    $where = $db->quoteInto('noble_title = ?', 'Sir');
    $order = 'first_name';
    $count = 10;
    $offset = 20;

    $rowset = $table->fetchAll($where, $order, $count, $offset);
    ?>

### 5.4.10. Adding Domain Logic

As a TableModule, Zend_Db_Table lends itself well to encapsulating your own particular domain logic. For example, you can override the insert() and update() methods to manipulate or validate the submitted data before it goes to the database.

    <?php
    class RoundTable extends Zend_Db_Table
    {
        public function insert($data)
        {
            // add a timestamp
            if (empty($data['created_on'])) {
                $data['created_on'] = time();
            }
            return parent::insert($data);
        }

        public function update($data)
        {
            // add a timestamp
            if (empty($data['updated_on'])) {
                $data['updated_on'] = time();
            }
            return parent::update($data);
        }
    }
    ?>

Similarly, you can add your own find() methods to look up records by something other than their primary key.

    <?php
    class RoundTable extends Zend_Db_Table
    {
        public function findAllWithName($name)
        {
            $db = $this->getAdapter();
            $where = $db->quoteInto("name = ?", $name);
            $order = "first_name";
            return $this->fetchAll($where, $order);
        }
    }
    ?>

Poprzedni | Początek rozdziału | Następny
5.3. Zend_Db_Select | Spis treści | 5.5. Zend_Db_Table_Row