From d06acd85cdfff5411474b46afee36fb77baa1200 Mon Sep 17 00:00:00 2001
From: Andrey Andreev <narf@bofh.bg>
Date: Fri, 25 May 2012 00:29:09 +0300
Subject: Added update_batch() support for PostgreSQL (issue #356)

---
 system/database/DB_utility.php                     |  4 +--
 system/database/drivers/postgre/postgre_driver.php | 41 ++++++++++++++++++++++
 user_guide_src/source/changelog.rst                |  2 ++
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/system/database/DB_utility.php b/system/database/DB_utility.php
index 587dfdc01..cb97ff448 100644
--- a/system/database/DB_utility.php
+++ b/system/database/DB_utility.php
@@ -212,7 +212,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 		$out = rtrim($out).$newline;
 
 		// Next blast through the result array and build out the rows
-		foreach ($query->result_array() as $row)
+		while ($row = $query->unbuffered_row('array'))
 		{
 			foreach ($row as $item)
 			{
@@ -258,7 +258,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 
 		// Generate the result
 		$xml = '<'.$root.'>'.$newline;
-		foreach ($query->result_array() as $row)
+		while ($row = $query->unbuffered_row())
 		{
 			$xml .= $tab.'<'.$element.'>'.$newline;
 			foreach ($row as $key => $val)
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 0ddfd0abe..30689cc70 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -538,6 +538,47 @@ class CI_DB_postgre_driver extends CI_DB {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * Update_Batch statement
+	 *
+	 * Generates a platform-specific batch update string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the update data
+	 * @param	array	the where clause
+	 * @return	string
+	 */
+	protected function _update_batch($table, $values, $index, $where = NULL)
+	{
+		$ids = array();
+		foreach ($values as $key => $val)
+		{
+			$ids[] = $val[$index];
+
+			foreach (array_keys($val) as $field)
+			{
+				if ($field != $index)
+				{
+					$final[$field][] =  'WHEN '.$val[$index].' THEN '.$val[$field];
+				}
+			}
+		}
+
+		$cases = '';
+		foreach ($final as $k => $v)
+		{
+			$cases .= $k.' = (CASE '.$k."\n"
+				.implode("\n", $v)."\n"
+				.'ELSE '.$k.' END), ';
+		}
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
+			.' WHERE '.(($where != '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
+			.$index.' IN('.implode(',', $ids).')';
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Delete statement
 	 *
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index f21f1266d..5407fb05e 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -75,6 +75,7 @@ Release Date: Not Released
 	 -  Added db_set_charset() support.
 	 -  Added _optimize_table() support for the :doc:`Database Utility Class <database/utilities>` (rebuilds table indexes).
 	 -  Added boolean data type support in escape().
+	 -  Added update_batch() support.
    -  Added a constructor to the DB_result class and moved all driver-specific properties and logic out of the base DB_driver class to allow better abstraction.
    -  Removed limit() and order_by() support for UPDATE and DELETE queries in PostgreSQL driver. Postgres does not support those features.
    -  Removed protect_identifiers() and renamed internal method _protect_identifiers() to it instead - it was just an alias.
@@ -218,6 +219,7 @@ Bug fixes for 3.0
 -  Fixed a bug (#44, #110) - :doc:`Upload library <libraries/file_uploading>`'s clean_file_name() method didn't clear '!' and '#' characters.
 -  Fixed a bug (#121) - ``CI_DB_result::row()`` returned an array when there's no actual result to be returned.
 -  Fixed a bug (#319) - SQLSRV's affected_rows() method failed due to a scrollable cursor being created for write-type queries.
+-  Fixed a bug (#356) - PostgreSQL driver didn't have an _update_batch() method, which resulted in fatal error being triggered when update_batch() is used with it.
 
 Version 2.1.1
 =============
-- 
cgit v1.2.3-24-g4f1b