139 lines
3.0 KiB
PHP
139 lines
3.0 KiB
PHP
<?php defined('SYSPATH') OR die('No direct script access.');
|
|
/**
|
|
* Database expressions can be used to add unescaped SQL fragments to a
|
|
* [Database_Query_Builder] object.
|
|
*
|
|
* For example, you can use an expression to generate a column alias:
|
|
*
|
|
* // SELECT CONCAT(first_name, last_name) AS full_name
|
|
* $query = DB::select(array(DB::expr('CONCAT(first_name, last_name)'), 'full_name')));
|
|
*
|
|
* More examples are available on the [Query Builder](database/query/builder#database-expressions) page
|
|
*
|
|
* @package Kohana/Database
|
|
* @category Base
|
|
* @author Kohana Team
|
|
* @copyright (c) 2009 Kohana Team
|
|
* @license http://kohanaphp.com/license
|
|
*/
|
|
class Kohana_Database_Expression {
|
|
|
|
// Unquoted parameters
|
|
protected $_parameters;
|
|
|
|
// Raw expression string
|
|
protected $_value;
|
|
|
|
/**
|
|
* Sets the expression string.
|
|
*
|
|
* $expression = new Database_Expression('COUNT(users.id)');
|
|
*
|
|
* @param string $value raw SQL expression string
|
|
* @param array $parameters unquoted parameter values
|
|
* @return void
|
|
*/
|
|
public function __construct($value, $parameters = array())
|
|
{
|
|
// Set the expression string
|
|
$this->_value = $value;
|
|
$this->_parameters = $parameters;
|
|
}
|
|
|
|
/**
|
|
* Bind a variable to a parameter.
|
|
*
|
|
* @param string $param parameter key to replace
|
|
* @param mixed $var variable to use
|
|
* @return $this
|
|
*/
|
|
public function bind($param, & $var)
|
|
{
|
|
$this->_parameters[$param] =& $var;
|
|
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Set the value of a parameter.
|
|
*
|
|
* @param string $param parameter key to replace
|
|
* @param mixed $value value to use
|
|
* @return $this
|
|
*/
|
|
public function param($param, $value)
|
|
{
|
|
$this->_parameters[$param] = $value;
|
|
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Add multiple parameter values.
|
|
*
|
|
* @param array $params list of parameter values
|
|
* @return $this
|
|
*/
|
|
public function parameters(array $params)
|
|
{
|
|
$this->_parameters = $params + $this->_parameters;
|
|
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Get the expression value as a string.
|
|
*
|
|
* $sql = $expression->value();
|
|
*
|
|
* @return string
|
|
*/
|
|
public function value()
|
|
{
|
|
return (string) $this->_value;
|
|
}
|
|
|
|
/**
|
|
* Return the value of the expression as a string.
|
|
*
|
|
* echo $expression;
|
|
*
|
|
* @return string
|
|
* @uses Database_Expression::value
|
|
*/
|
|
public function __toString()
|
|
{
|
|
return $this->value();
|
|
}
|
|
|
|
/**
|
|
* Compile the SQL expression and return it. Replaces any parameters with
|
|
* their given values.
|
|
*
|
|
* @param mixed Database instance or name of instance
|
|
* @return string
|
|
*/
|
|
public function compile($db = NULL)
|
|
{
|
|
if ( ! is_object($db))
|
|
{
|
|
// Get the database instance
|
|
$db = Database::instance($db);
|
|
}
|
|
|
|
$value = $this->value();
|
|
|
|
if ( ! empty($this->_parameters))
|
|
{
|
|
// Quote all of the parameter values
|
|
$params = array_map(array($db, 'quote'), $this->_parameters);
|
|
|
|
// Replace the values in the expression
|
|
$value = strtr($value, $params);
|
|
}
|
|
|
|
return $value;
|
|
}
|
|
|
|
} // End Database_Expression
|