Zend Framework教程-Zend_Db-数据库操作1-Zend_Db_Adapter

上一节，大概了解了Zend Framework完成数据库操作的常用类，下面一一简单介绍其用法。

Zend_Db_Adapter是我们操作数据库的常用方式，以下是几个比较重要的功能使用说明：

1.建立数据库链接

		require_once 'Zend/Db.php';		$params = array ('host'     => '127.0.0.1',		                 'username' => 'root',		                 'password' => '',		                 'dbname'   => 'test');				$db = Zend_Db::factory('PDO_MYSQL', $params);

    public static function factory($adapter, $config = array())

第一个参数是采用何种方式链接。

第二个参数是指定传递的链接参数。

我们采用的是‘PDO_MYSQL’连接方式。具体参数规则如下：

/*         * Form full adapter class name         */        $adapterNamespace = 'Zend_Db_Adapter';        if (isset($config['adapterNamespace'])) {            if ($config['adapterNamespace'] != '') {                $adapterNamespace = $config['adapterNamespace'];            }            unset($config['adapterNamespace']);        }        // Adapter no longer normalized- see http://framework.zend.com/issues/browse/ZF-5606        $adapterName = $adapterNamespace . '_';        $adapterName .= str_replace(' ', '_', ucwords(str_replace('_', ' ', strtolower($adapter))));        /*         * Load the adapter class.  This throws an exception         * if the specified class cannot be loaded.         */        if (!class_exists($adapterName)) {            require_once 'Zend/Loader.php';            Zend_Loader::loadClass($adapterName);        }

以下是常见的方式,取Zend_Db_Adapter_后面的名字作为参数。

Zend_Db_Adapter_Pdo_Sqlite

Zend_Db_Adapter_Pdo_Pgsql

Zend_Db_Adapter_Pdo_Mssql

Zend_Db_Adapter_Mysqli

Zend_Db_Adapter_Db2

Zend_Db_Adapter_Oracle

Zend_Db_Adapter_Sqlsrv

具体的配置参数可以使用查看Zend_Db_Adapter_Abstract源码的$config。当然你可以把配置参数放到application.ini配置文件，这里不再累述。

具体的实现方法如下：

 /**     * Factory for Zend_Db_Adapter_Abstract classes.     *     * First argument may be a string containing the base of the adapter class     * name, e.g. 'Mysqli' corresponds to class Zend_Db_Adapter_Mysqli.  This     * name is currently case-insensitive, but is not ideal to rely on this behavior.     * If your class is named 'My_Company_Pdo_Mysql', where 'My_Company' is the namespace     * and 'Pdo_Mysql' is the adapter name, it is best to use the name exactly as it     * is defined in the class.  This will ensure proper use of the factory API.     *     * First argument may alternatively be an object of type Zend_Config.     * The adapter class base name is read from the 'adapter' property.     * The adapter config parameters are read from the 'params' property.     *     * Second argument is optional and may be an associative array of key-value     * pairs.  This is used as the argument to the adapter constructor.     *     * If the first argument is of type Zend_Config, it is assumed to contain     * all parameters, and the second argument is ignored.     *     * @param  mixed $adapter String name of base adapter class, or Zend_Config object.     * @param  mixed $config  OPTIONAL; an array or Zend_Config object with adapter parameters.     * @return Zend_Db_Adapter_Abstract     * @throws Zend_Db_Exception     */    public static function factory($adapter, $config = array())    {        if ($config instanceof Zend_Config) {            $config = $config->toArray();        }        /*         * Convert Zend_Config argument to plain string         * adapter name and separate config object.         */        if ($adapter instanceof Zend_Config) {            if (isset($adapter->params)) {                $config = $adapter->params->toArray();            }            if (isset($adapter->adapter)) {                $adapter = (string) $adapter->adapter;            } else {                $adapter = null;            }        }        /*         * Verify that adapter parameters are in an array.         */        if (!is_array($config)) {            /**             * @see Zend_Db_Exception             */            require_once 'Zend/Db/Exception.php';            throw new Zend_Db_Exception('Adapter parameters must be in an array or a Zend_Config object');        }        /*         * Verify that an adapter name has been specified.         */        if (!is_string($adapter) || empty($adapter)) {            /**             * @see Zend_Db_Exception             */            require_once 'Zend/Db/Exception.php';            throw new Zend_Db_Exception('Adapter name must be specified in a string');        }        /*         * Form full adapter class name         */        $adapterNamespace = 'Zend_Db_Adapter';        if (isset($config['adapterNamespace'])) {            if ($config['adapterNamespace'] != '') {                $adapterNamespace = $config['adapterNamespace'];            }            unset($config['adapterNamespace']);        }        // Adapter no longer normalized- see http://framework.zend.com/issues/browse/ZF-5606        $adapterName = $adapterNamespace . '_';        $adapterName .= str_replace(' ', '_', ucwords(str_replace('_', ' ', strtolower($adapter))));        /*         * Load the adapter class.  This throws an exception         * if the specified class cannot be loaded.         */        if (!class_exists($adapterName)) {            require_once 'Zend/Loader.php';            Zend_Loader::loadClass($adapterName);        }        /*         * Create an instance of the adapter class.         * Pass the config to the adapter class constructor.         */        $dbAdapter = new $adapterName($config);        /*         * Verify that the object created is a descendent of the abstract adapter type.         */        if (! $dbAdapter instanceof Zend_Db_Adapter_Abstract) {            /**             * @see Zend_Db_Exception             */            require_once 'Zend/Db/Exception.php';            throw new Zend_Db_Exception("Adapter class '$adapterName' does not extend Zend_Db_Adapter_Abstract");        }        return $dbAdapter;    }

2.常见的方法

主要在Zend_Db_Adapter_Abstract抽象父类和具体的实现类。

以pdo方式的mysql文件，说明常用的功能：

<?phpabstract class Zend_Db_Adapter_Abstract{    public function query($sql, $bind = array())     public function beginTransaction()     public function commit()     public function rollBack()     public function insert($table, array $bind)     public function update($table, array $bind, $where = '')     public function delete($table, $where = '')     public function select()     public function getFetchMode()     public function fetchAll($sql, $bind = array(), $fetchMode = null)     public function fetchRow($sql, $bind = array(), $fetchMode = null)     public function fetchAssoc($sql, $bind = array())     public function fetchCol($sql, $bind = array())     public function fetchPairs($sql, $bind = array())     public function fetchOne($sql, $bind = array())     public function quote($value, $type = null)     public function quoteInto($text, $value, $type = null, $count = null)     public function quoteIdentifier($ident, $auto=false)     public function quoteColumnAs($ident, $alias, $auto=false)     public function quoteTableAs($ident, $alias = null, $auto = false) }

<?phpabstract class Zend_Db_Adapter_Pdo_Abstract extends Zend_Db_Adapter_Abstract{     public function isConnected()     public function closeConnection()     public function prepare($sql)     public function lastInsertId($tableName = null, $primaryKey = null)     public function query($sql, $bind = array())     public function exec($sql)     public function setFetchMode($mode)     public function supportsParameters($type)     public function getServerVersion() }

<?phpclass Zend_Db_Adapter_Pdo_Mysql extends Zend_Db_Adapter_Pdo_Abstract{       public function limit($sql, $count, $offset = 0)}

3.常见的方法的使用举例

<?php// 创建一个$db对象,假设数据库adapter为mysql.// 为标量加引号$value = $db->quote('St John"s Wort');// $value 现在变成了 '"St John"s Wort"' (注意两边的引号)// 为数组加引号$value = $db->quote(array('a', 'b', 'c');// $value 现在变成了 '"a", "b", "c"' (","分隔的字符串)?>

<?php// 创建一个$db对象,假设数据库adapter为mysql.// 在where语句中为标量加上引号$where = $db->quoteInto('id = ?', 1);// $where 现在为 'id = "1"' (注意两边的引号)// 在where语句中为数组加上引号$where = $db->quoteInto('id IN(?)', array(1, 2, 3));// $where 现在为 'id IN("1", "2", "3")' (一个逗号分隔的字符串)?>

<?php// 创建一个$db对象,然后查询数据库// 使用完整的sql语句直接进行查询.$sql = $db->quoteInto(    'SELECT * FROM example WHERE date > ?',    '2006-01-01');$result = $db->query($sql);// 使用PDOStatement对象$result将所有结果数据放到一个数组中$rows = $result->fetchAll();?>

<?php// 创建一个$db对象,然后查询数据库.// 这一次，使用绑定的占位符.$result = $db->query(    'SELECT * FROM example WHERE date > :placeholder',    array('placeholder' => '2006-01-01'));// 使用PDOStatement对象$result将所有结果数据放到一个数组中$rows = $result->fetchAll();?>

<?php// 创建一个$db对象,然后查询数据库.// 这次, 设定一个 PDOStatement 对象进行手工绑定.$stmt = $db->prepare('SELECT * FROM example WHERE date > :placeholder');$stmt->bindValue('placeholder', '2006-01-01');$stmt->execute();// 使用PDOStatement对象$result将所有结果数据放到一个数组中$rows = $stmt->fetchAll();?>

<?php// 创建一个 $db对象, 然后开始做一个事务处理.$db->beginTransaction();// 尝试数据库操作.// 假如成功,commit该操作;// 假如, roll back.try {    $db->query(...);    $db->commit();} catch (Exception $e) {    $db->rollBack();    echo $e->getMessage();}?>

<?php//// INSERT INTO round_table//     (noble_title, first_name, favorite_color)//     VALUES ("King", "Arthur", "blue");//// 创建一个 $db对象, 然后...// 以"列名"=>"数据"的格式格式构造插入数组,插入数据行$row = array (    'noble_title'    => 'King',    'first_name'     => 'Arthur',    'favorite_color' => 'blue',);// 插入数据的数据表$table = 'round_table';// i插入数据行并返回行数$rows_affected = $db->insert($table, $row);$last_insert_id = $db->lastInsertId();?>

<?php//// UPDATE round_table//     SET favorite_color = "yellow"//     WHERE first_name = "Robin";//// 创建一个 $db对象, 然后...// 以"列名"=>"数据"的格式构造更新数组,更新数据行$set = array (    'favorite_color' => 'yellow',);// 更新的数据表$table = 'round_table';// where语句$where = $db->quoteInto('first_name = ?', 'Robin');// 更新表数据,返回更新的行数$rows_affected = $db->update($table, $set, $where);?>

<?php//// 需要删除数据的表//     WHERE first_name = "Patsy";//// 创建一个 $db对象, 然后...// 设定需要删除数据的表$table = 'round_table';// where条件语句$where = $db->quoteInto('first_name = ?', 'Patsy');// 删除数据并得到影响的行数$rows_affected = $db->delete($table, $where);?>

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