Add join() USING support

2 files changed, 12 insertions, 3 deletions

diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 27f9f363b..4c54b1c0a 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -368,12 +368,20 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				$newcond .= $m[0][$i][0];
 			}
 
-			$cond = $newcond;
+			$cond = ' ON '.$newcond;
 		}
 		// Split apart the condition and protect the identifiers
 		elseif ($escape === TRUE && preg_match('/([\[\w\.-]+)([\W\s]+)(.+)/i', $cond, $match))
 		{
-			$cond = $this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+			$cond = ' ON '.$this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+		}
+		elseif ( ! $this->_has_operator($cond))
+		{
+			$cond = ' USING ('.($escape ? $this->escape_identifiers($cond) : $cond).')';
+		}
+		else
+		{
+			$cond = ' ON '.$cond;
 		}
 
 		// Do we want to escape the table name?
@@ -383,7 +391,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		}
 
 		// Assemble the JOIN statement
-		$this->qb_join[] = $join = $type.'JOIN '.$table.' ON '.$cond;
+		$this->qb_join[] = $join = $type.'JOIN '.$table.$cond;
 
 		if ($this->qb_caching === TRUE)
 		{
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 4054a04ff..b39d43b1a 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -79,6 +79,7 @@ Release Date: Not Released
 	 - Added new methods that return the SQL string of queries without executing them: get_compiled_select(), get_compiled_insert(), get_compiled_update(), get_compiled_delete().
 	 - Added an optional parameter that allows to disable escaping (useful for custom fields) for methods join(), order_by(), where_in(), or_where_in(), where_not_in(), or_where_not_in().
 	 - Added support for join() with multiple conditions.
+	 - Added support for USING in join().
    -  Improved support for the MySQLi driver, including:
 	 - OOP style of the PHP extension is now used, instead of the procedural aliases.
 	 - Server version checking is now done via ``mysqli::$server_info`` instead of running an SQL query.