Index: branches/5.3.x/core/kernel/db/i_db_connection.php
===================================================================
diff -u -N -r15919 -r15922
--- branches/5.3.x/core/kernel/db/i_db_connection.php	(.../i_db_connection.php)	(revision 15919)
+++ branches/5.3.x/core/kernel/db/i_db_connection.php	(.../i_db_connection.php)	(revision 15922)
@@ -21,33 +21,135 @@
 	interface IDBConnection {
 
 		/**
-		 * Performs sql query, that will change database content
+		 * Checks if previous query execution raised an error.
 		 *
+		 * @return bool
+		 * @access public
+		 */
+		public function hasError();
+
+		/**
+		 * Checks if connection to database is opened.
+		 *
+		 * @return bool
+		 * @access public
+		 */
+		public function connectionOpened();
+
+		/**
+		 * Setups the connection according given configuration.
+		 *
+		 * @param Array $config
+		 * @return bool
+		 * @access public
+		 */
+		public function setup($config);
+
+		/**
+		 * Returns first field of first line of recordset if query ok or false otherwise.
+		 *
 		 * @param string $sql
+		 * @param int $offset
+		 * @return string
+		 * @access public
+		 */
+		public function GetOne($sql, $offset = 0);
+
+		/**
+		 * Returns first row of recordset if query ok, false otherwise.
+		 *
+		 * @param string $sql
+		 * @param int $offset
+		 * @return Array
+		 * @access public
+		 */
+		public function GetRow($sql, $offset = 0);
+
+		/**
+		 * Returns 1st column of recordset as one-dimensional array or false otherwise.
+		 *
+		 * Optional parameter $key_field can be used to set field name to be used as resulting array key.
+		 *
+		 * @param string $sql
+		 * @param string $key_field
+		 * @return Array
+		 * @access public
+		 */
+		public function GetCol($sql, $key_field = null);
+
+		/**
+		 * Returns iterator for 1st column of a recordset or false in case of error.
+		 *
+		 * Optional parameter $key_field can be used to set field name to be used as resulting array key.
+		 *
+		 * @param string $sql
+		 * @param string $key_field
+		 * @return bool|kMySQLQueryCol
+		 */
+		public function GetColIterator($sql, $key_field = null);
+
+		/**
+		 * Queries db with $sql query supplied and returns rows selected if any, false otherwise.
+		 *
+		 * Optional parameter $key_field allows to set one of the query fields value as key in string array.
+		 *
+		 * @param string $sql
+		 * @param string $key_field
+		 * @param bool $no_debug
+		 * @return Array
+		 * @access public
+		 */
+		public function Query($sql, $key_field = null, $no_debug = false);
+
+		/**
+		 * Returns iterator to a recordset, produced from running $sql query.
+		 *
+		 * Queries db with $sql query supplied and returns kMySQLQuery iterator or false in case of error.
+		 * Optional parameter $key_field allows to set one of the query fields value as key in string array.
+		 *
+		 * @param string $sql
+		 * @param string $key_field
+		 * @param bool   $no_debug
+		 * @param string $iterator_class
+		 * @return kMySQLQuery|bool
+		 * @access public
+		 */
+		public function GetIterator($sql, $key_field = null, $no_debug = false, $iterator_class = 'kMySQLQuery');
+
+		/**
+		 * Free memory used to hold recordset handle.
+		 *
+		 * @access public
+		 */
+		public function Destroy();
+
+		/**
+		 * Performs sql query, that will change database content.
+		 *
+		 * @param string $sql
 		 * @return bool
 		 * @access public
 		 */
 		public function ChangeQuery($sql);
 
 		/**
-		 * Returns auto increment field value from
-		 * insert like operation if any, zero otherwise
+		 * Returns auto increment field value from insert like operation if any, zero otherwise.
 		 *
 		 * @return int
 		 * @access public
 		 */
 		public function getInsertID();
 
 		/**
-		 * Returns row count affected by last query
+		 * Returns row count affected by last query.
 		 *
 		 * @return int
 		 * @access public
 		 */
 		public function getAffectedRows();
 
 		/**
-		 * Returns LIMIT sql clause part for specific db
+		 * Returns LIMIT sql clause part for specific db.
 		 *
 		 * @param int $offset
 		 * @param int $rows
@@ -57,8 +159,7 @@
 		public function getLimitClause($offset, $rows);
 
 		/**
-		 * If it's a string, adds quotes and backslashes (only work since PHP 4.3.0)
-		 * Otherwise returns as-is
+		 * If it's a string, adds quotes and backslashes. Otherwise returns as-is.
 		 *
 		 * @param mixed $string
 		 * @return string
@@ -67,7 +168,7 @@
 		public function qstr($string);
 
 		/**
-		 * Calls "qstr" function for each given array element
+		 * Calls "qstr" function for each given array element.
 		 *
 		 * @param Array $array
 		 * @param string $function
@@ -76,7 +177,7 @@
 		public function qstrArray($array, $function = 'qstr');
 
 		/**
-		 * Escapes strings (only work since PHP 4.3.0)
+		 * Escapes string.
 		 *
 		 * @param mixed $string
 		 * @return string
@@ -85,15 +186,15 @@
 		public function escape($string);
 
 		/**
-		 * Returns last error code occurred
+		 * Returns last error code occurred.
 		 *
 		 * @return int
 		 * @access public
 		 */
 		public function getErrorCode();
 
 		/**
-		 * Returns last error message
+		 * Returns last error message.
 		 *
 		 * @return string
 		 * @access public
@@ -102,7 +203,7 @@
 
 		/**
 		 * Performs insert of given data (useful with small number of queries)
-		 * or stores it to perform multiple insert later (useful with large number of queries)
+		 * or stores it to perform multiple insert later (useful with large number of queries).
 		 *
 		 * @param Array $fields_hash
 		 * @param string $table
@@ -114,7 +215,7 @@
 		public function doInsert($fields_hash, $table, $type = 'INSERT', $insert_now = true);
 
 		/**
-		 * Update given field values to given record using $key_clause
+		 * Update given field values to given record using $key_clause.
 		 *
 		 * @param Array $fields_hash
 		 * @param string $table
@@ -125,7 +226,7 @@
 		public function doUpdate($fields_hash, $table, $key_clause);
 
 		/**
-		 * Allows to detect table's presence in database
+		 * Allows to detect table's presence in database.
 		 *
 		 * @param string $table_name
 		 * @param bool $force
@@ -135,15 +236,15 @@
 		public function TableFound($table_name, $force = false);
 
 		/**
-		 * Returns query processing statistics
+		 * Returns query processing statistics.
 		 *
 		 * @return Array
 		 * @access public
 		 */
 		public function getQueryStatistics();
 
 		/**
-		 * Get status information from SHOW STATUS in an associative array
+		 * Get status information from SHOW STATUS in an associative array.
 		 *
 		 * @param string $which
 		 * @return Array