adds comments for phpDoc

git-svn-id: http://xe-core.googlecode.com/svn/branches/1.5.0@10739 201d5d3c-b55e-5fd7-737f-ddc643e51545

classes/db/queryparts/expression/Expression.class.php

@@ -1,18 +1,28 @@
 <?php
 	/**
-	 * @class Expression
-	 * @author Corina
-	 * @brief Represents an expression used in select/update/insert/delete statements
+	 * Expression
+	 * Represents an expression used in select/update/insert/delete statements
 	 * 
 	 *  Examples (expressions are inside double square brackets):
 	 *  	select [[columnA]], [[columnB as aliasB]] from tableA
 	 *  	update tableA set [[columnA = valueA]] where columnB = something
 	 *
+	 * @author Corina
+	 * @package /classes/db/queryparts/expression
+	 * @version 0.1
 	 */
-
 	class Expression {
+		/**
+		 * column name
+		 * @var string
+		 */
 		var $column_name;
 		
+		/**
+		 * constructor
+		 * @param string $column_name
+		 * @return void
+		 */
 		function Expression($column_name){
 			$this->column_name = $column_name;
 		}
@@ -25,6 +35,10 @@
 			return false;
 		}
 		
+		/**
+		 * Return column expression, ex) column as alias
+		 * @return string
+		 */
 		function getExpression() {
 		}
-	}
+	}