Adding file I missed in previous commit

lib/Cake/Model/Datasource/Database/FunctionsTrait.php

@@ -0,0 +1,69 @@
+<?php
+/**
+ *
+ * PHP Version 5.4
+ *
+ * CakePHP(tm) Tests <http://book.cakephp.org/2.0/en/development/testing.html>
+ * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The Open Group Test Suite License
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright 2005-2013, Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://book.cakephp.org/2.0/en/development/testing.html CakePHP(tm) Tests
+ * @package       Cake.Test.Case.Model.Datasource.Database
+ * @since         CakePHP(tm) v 3.0
+ * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
+ */
+namespace Cake\Model\Datasource\Database;
+use Cake\Model\Datasource\Database\Expression\FunctionExpression;
+
+trait FunctionsTrait {
+
+/**
+ * Returns a new instance of a FunctionExpression. This is used for generating
+ * arbitrary function calls in the final SQL string.
+ *
+ * @param string $name the name of the SQL function to constructed
+ * @param array $params list of params to be passed to the function
+ * @param array $types list of types for each function param
+ * @return FunctionExpression
+ */
+	public function func($name, $params = [], $types = []) {
+		return new FunctionExpression($name, $params, $types);
+	}
+
+	protected function _literalArgumentFunction($name, $expression, $types = []) {
+		if (!is_string($expression)) {
+			$expression = [$expression];
+		} else {
+			$expression = [$expression => 'literal'];
+		}
+		return $this->func($name, $expression, $types);
+	}
+
+	public function sum($expression, $types = []) {
+		return $this->_literalArgumentFunction('SUM', $expression, $types);
+	}
+
+	public function avg($expression, $types = []) {
+		return $this->_literalArgumentFunction('AVG', $expression, $types);
+	}
+
+	public function max($expression, $types = []) {
+		return $this->_literalArgumentFunction('MAX', $expression, $types);
+	}
+
+	public function min($expression, $types = []) {
+		return $this->_literalArgumentFunction('MIN', $expression, $types);
+	}
+
+	public function count($expression, $types = []) {
+		return $this->_literalArgumentFunction('COUNT', $expression, $types);
+	}
+
+	public function concat($args, $types = []) {
+		return $this->func('CONCAT', $args, $types);
+	}
+
+}