<?php
/**
* CSqlDataProvider implements a data provider based on a plain SQL statement.
*
* CSqlDataProvider provides data in terms of arrays, each representing a row of query result.
*
* Like other data providers, CSqlDataProvider also supports sorting and pagination.
* It does so by modifying the given {@link sql} statement with "ORDER BY" and "LIMIT"
* clauses. You may configure the {@link sort} and {@link pagination} properties to
* customize sorting and pagination behaviors.
*
* CSqlDataProvider may be used in the following way:
* <pre>
* $count=Yii::app()->db->createCommand('SELECT COUNT(*) FROM tbl_user')->queryScalar();
* $sql='SELECT * FROM tbl_user';
* $dataProvider=new CSqlDataProvider($sql, array(
* 'totalItemCount'=>$count,
* 'sort'=>array(
* 'attributes'=>array(
* 'id', 'username', 'email',
* ),
* ),
* 'pagination'=>array(
* 'pageSize'=>10,
* ),
* ));
* // $dataProvider->getData() will return a list of arrays.
* </pre>
*
* Note: if you want to use the pagination feature, you must configure the {@link totalItemCount} property
* to be the total number of rows (without pagination). And if you want to use the sorting feature,
* you must configure {@link sort} property so that the provider knows which columns can be sorted.
*
* @author Qiang Xue <[email protected]>
* @package system.web
* @since 1.1.4
*/
class CSqlDataProvider extends CDataProvider
{
/**
* @var CDbConnection the database connection to be used in the queries.
* Defaults to null, meaning using Yii::app()->db.
*/
public $db;
/**
* @var string|CDbCommand the SQL statement to be used for fetching data rows.
* Since version 1.1.13 this can also be an instance of {@link CDbCommand}.
*/
public $sql;
/**
* @var array parameters (name=>value) to be bound to the SQL statement.
*/
public $params=array();
/**
* @var string the name of key field. Defaults to 'id'.
*/
public $keyField='id';
/**
* Constructor.
* @param string|CDbCommand $sql the SQL statement to be used for fetching data rows. Since version 1.1.13 this can also be an instance of {@link CDbCommand}.
* @param array $config configuration (name=>value) to be applied as the initial property values of this class.
*/
public function __construct($sql,$config=array())
{
$this->sql=$sql;
foreach($config as $key=>$value)
$this->$key=$value;
}
/**
* Fetches the data from the persistent data storage.
* @return array list of data items
*/
protected function fetchData()
{
if(!($this->sql instanceof CDbCommand))
{
$db=$this->db===null ? Yii::app()->db : $this->db;
$command=$db->createCommand($this->sql);
}
else
$command=clone $this->sql;
if(($sort=$this->getSort())!==false)
{
$order=$sort->getOrderBy();
if(!empty($order))
{
if(preg_match('/\s+order\s+by\s+[\w\s,]+$/i',$command->text))
$command->text.=', '.$order;
else
$command->text.=' ORDER BY '.$order;
}
}
if(($pagination=$this->getPagination())!==false)
{
$pagination->setItemCount($this->getTotalItemCount());
$limit=$pagination->getLimit();
$offset=$pagination->getOffset();
$command->text=$command->getConnection()->getCommandBuilder()->applyLimit($command->text,$limit,$offset);
}
foreach($this->params as $name=>$value)
$command->bindValue($name,$value);
return $command->queryAll();
}
/**
* Fetches the data item keys from the persistent data storage.
* @return array list of data item keys.
*/
protected function fetchKeys()
{
$keys=array();
foreach($this->getData() as $i=>$data)
$keys[$i]=$data[$this->keyField];
return $keys;
}
/**
* Calculates the total number of data items.
* This method is invoked when {@link getTotalItemCount()} is invoked
* and {@link totalItemCount} is not set previously.
* The default implementation simply returns 0.
* You may override this method to return accurate total number of data items.
* @return integer the total number of data items.
*/
protected function calculateTotalItemCount()
{
return 0;
}
}