changes for enhanced database compatibility
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 7aab37e..8f63c25 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -556,7 +556,7 @@
 		}	

 

 		// This function may get "item1 item2" as a string, and so

-		// we may need "`item1` `item2`" and not "`item1 item2`"

+		// we may need ""item1" "item2"" and not ""item1 item2""

 		if (ctype_alnum($item) === FALSE)

 		{

 			if (strpos($item, '.') !== FALSE)

@@ -566,14 +566,14 @@
 				$item = (strpos($aliased_tables, $table_name) !== FALSE) ? $item = $item : $this->dbprefix.$item;

 			}

 

-			// This function may get "field >= 1", and need it to return "`field` >= 1"

+			// This function may get "field >= 1", and need it to return ""field" >= 1"

 			$lbound = ($first_word_only === TRUE) ? '' : '|\s|\(';

 

-			$item = preg_replace('/(^'.$lbound.')([\w\d\-\_]+?)(\s|\)|$)/iS', '$1`$2`$3', $item);

+			$item = preg_replace('/(^'.$lbound.')([\w\d\-\_]+?)(\s|\)|$)/iS', '$1"$2"$3', $item);

 		}

 		else

 		{

-			return "`{$item}`";

+			return "\"{$item}\"";

 		}

 

 		$exceptions = array('AS', '/', '-', '%', '+', '*');

@@ -581,9 +581,9 @@
 		foreach ($exceptions as $exception)

 		{

 		

-			if (stristr($item, " `{$exception}` ") !== FALSE)

+			if (stristr($item, " \"{$exception}\" ") !== FALSE)

 			{

-				$item = preg_replace('/ `('.preg_quote($exception).')` /i', ' $1 ', $item);

+				$item = preg_replace('/ "('.preg_quote($exception).')" /i', ' $1 ', $item);

 			}

 		}

 		return $item;

@@ -608,7 +608,7 @@
 			$tables = array($tables);

 		}

 		

-		return '('.implode(', ', $tables).')';

+		return implode(', ', $tables);

 	}

 

 	// --------------------------------------------------------------------