Added KH 3.3.0

includes/kohana/modules/database/classes/Kohana/Database/Expression.php

@@ -0,0 +1,138 @@
+<?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