Refactored DB Forge

- PDO subdrivers are isolated from each other now.
- Added compatibility for pretty much all of the features, for every DB platform.
- Unified the way that stuff works in general.
- Fixes issue #1005.

1 files changed, 26 insertions, 4 deletions

diff --git a/user_guide_src/source/installation/upgrade_300.rst b/user_guide_src/source/installation/upgrade_300.rst
index fd5eea478..4e0b952d5 100644
--- a/user_guide_src/source/installation/upgrade_300.rst
+++ b/user_guide_src/source/installation/upgrade_300.rst
@@ -93,9 +93,31 @@ Step 8: Check the calls to Array Helper's element() and elements() functions
 The default return value of these functions, when the required elements
 don't exist, has been changed from FALSE to NULL.
 
-**********************************************************
-Step 9: Change usage of Email library with multiple emails
-**********************************************************
+************************************************************
+Step 9: Update usage of Database Forge's drop_table() method
+************************************************************
+
+Up until now, ``drop_table()`` added an IF EXISTS clause by default or it didn't work
+at all with some drivers. In CodeIgniter 3.0, the IF EXISTS condition is no longer added
+by deafault and has an optional second parameter that allows that instead and is set to
+FALSE by default.
+
+If your application relies on IF EXISTS, you'll have to change its usage.
+
+::
+
+	// Now produces just DROP TABLE `table_name`
+	$this->dbforge->drop_table('table_name');
+
+	// Produces DROP TABLE IF EXISTS `table_name`
+	$this->dbforge->drop_table('table_name', TRUE);
+
+.. note:: The given example users MySQL-specific syntax, but it should work across
+	all drivers with the exception of ODBC.
+
+***********************************************************
+Step 10: Change usage of Email library with multiple emails
+***********************************************************
 
 The :doc:`Email library <../libraries/email>` will automatically clear the
 set parameters after successfully sending emails. To override this behaviour,
@@ -110,7 +132,7 @@ pass FALSE as the first parameter in the ``send()`` method:
 
 
 ****************************************************************
-Step 10: Remove usage of (previously) deprecated functionalities
+Step 11: Remove usage of (previously) deprecated functionalities
 ****************************************************************
 
 In addition to the ``$autoload['core']`` configuration setting, there's a number of other functionalities