From 83c6429c4c68ae5e8396829f6d8cce5002e9c25a Mon Sep 17 00:00:00 2001
From: Deon George <deon@leenooks.net>
Date: Wed, 30 Sep 2015 21:46:03 +1000
Subject: [PATCH] Work in Progress

---
 classes/Database/Query/Builder/Select.php | 125 ++++++++++++++++++++++
 classes/Kohana/Database/DB2.php           |  59 +++++++++-
 config/database.php                       |   1 +
 3 files changed, 182 insertions(+), 3 deletions(-)
 create mode 100644 classes/Database/Query/Builder/Select.php

diff --git a/classes/Database/Query/Builder/Select.php b/classes/Database/Query/Builder/Select.php
new file mode 100644
index 0000000..74f5ad8
--- /dev/null
+++ b/classes/Database/Query/Builder/Select.php
@@ -0,0 +1,125 @@
+<?php defined('SYSPATH') OR die('No direct script access.');
+/**
+ * Database query builder for SELECT statements. See [Query Builder](/database/query/builder) for usage and examples.
+ *
+ * @package    Kohana/Database
+ * @category   Query
+ * @author     Kohana Team
+ * @copyright  (c) 2008-2009 Kohana Team
+ * @license    http://kohanaphp.com/license
+ */
+class Database_Query_Builder_Select extends Kohana_Database_Query_Builder_Select {
+
+	/**
+	 * Compile the SQL query and return it.
+	 *
+	 * For DB2 we need to override the LIMIT parameter.
+	 *
+	 * @param   mixed  $db  Database instance or name of instance
+	 * @return  string
+	 */
+	public function compile($db = NULL)
+	{
+		if ( ! is_object($db))
+		{
+			// Get the database instance
+			$db = Database::instance($db);
+		}
+
+		if (! $db instanceof Database_DB2)
+			return parent::compile($db);
+
+		// Callback to quote columns
+		$quote_column = array($db, 'quote_column');
+
+		// Callback to quote tables
+		$quote_table = array($db, 'quote_table');
+
+		// Start a selection query
+		$query = 'SELECT ';
+
+		if ($this->_distinct === TRUE)
+		{
+			// Select only unique results
+			$query .= 'DISTINCT ';
+		}
+
+		if (empty($this->_select))
+		{
+			// Select all columns
+			$query .= '*';
+		}
+		else
+		{
+			// Select all columns
+			$query .= implode(', ', array_unique(array_map($quote_column, $this->_select)));
+		}
+
+		if ( ! empty($this->_from))
+		{
+			// Set tables to select from
+			$query .= ' FROM '.implode(', ', array_unique(array_map($quote_table, $this->_from)));
+		}
+
+		if ( ! empty($this->_join))
+		{
+			// Add tables to join
+			$query .= ' '.$this->_compile_join($db, $this->_join);
+		}
+
+		if ( ! empty($this->_where))
+		{
+			// Add selection conditions
+			$query .= ' WHERE '.$this->_compile_conditions($db, $this->_where);
+		}
+
+		if ( ! empty($this->_group_by))
+		{
+			// Add grouping
+			$query .= ' '.$this->_compile_group_by($db, $this->_group_by);
+		}
+
+		if ( ! empty($this->_having))
+		{
+			// Add filtering conditions
+			$query .= ' HAVING '.$this->_compile_conditions($db, $this->_having);
+		}
+
+		if ( ! empty($this->_order_by))
+		{
+			// Add sorting
+			$query .= ' '.$this->_compile_order_by($db, $this->_order_by);
+		}
+
+		if ($this->_limit !== NULL)
+		{
+			// Add limiting
+			$query .= ' FETCH FIRST '.$this->_limit.' ROWS ONLY';
+		}
+
+		if ($this->_offset !== NULL)
+		{
+			// Add offsets
+			$query .= ' OFFSET '.$this->_offset;
+		}
+
+		if ( ! empty($this->_union))
+		{
+			foreach ($this->_union as $u) {
+				$query .= ' UNION ';
+				if ($u['all'] === TRUE)
+				{
+					$query .= 'ALL ';
+				}
+				$query .= $u['select']->compile($db);
+			}
+		}
+
+		$this->_sql = $query;
+
+		// Cant run through parent, as it overwrites our LIMIT syntax.
+		// return parent::compile($db);
+		return $query;
+	}
+} // End Database_Query_Select
+?>
diff --git a/classes/Kohana/Database/DB2.php b/classes/Kohana/Database/DB2.php
index c699e4e..c31935f 100644
--- a/classes/Kohana/Database/DB2.php
+++ b/classes/Kohana/Database/DB2.php
@@ -16,8 +16,8 @@ class Kohana_Database_DB2 extends Database {
 	// Identifier for this connection within the PHP driver
 	protected $_connection_id;
 
-	// DB2 uses a " for identifiers
-	protected $_identifier = '"';
+	// DB2 doesnt use identifies identifiers
+	protected $_identifier = '';
 
 	// Required Abstract Classes
 	public function begin($mode = NULL) {}
@@ -229,6 +229,59 @@ class Kohana_Database_DB2 extends Database {
 
 	public function quote_column($column)
 	{
+		// Identifiers are escaped by repeating them
+		$escaped_identifier = $this->_identifier.$this->_identifier;
+
+		if (is_array($column)) {
+			list($column, $alias) = $column;
+			$alias = str_replace($this->_identifier, $escaped_identifier, $alias);
+		}
+
+		if ($column instanceof Database_Query) {
+			// Create a sub-query
+			$column = '('.$column->compile($this).')';
+
+		} elseif ($column instanceof Database_Expression) {
+			// Compile the expression
+			$column = $column->compile($this);
+
+		} else {
+			// Convert to a string
+			$column = (string) $column;
+
+			$column = str_replace($this->_identifier, $escaped_identifier, $column);
+
+			if ($column === '*') {
+				return $column;
+
+			} elseif (strpos($column, '.') !== FALSE) {
+				$parts = explode('.', $column);
+
+				if ($prefix = $this->table_prefix()) {
+					// Get the offset of the table name, 2nd-to-last part
+					$offset = count($parts) - 2;
+
+					// Add the table prefix to the table name
+					$parts[$offset] = $prefix.$parts[$offset];
+				}
+
+				foreach ($parts as & $part) {
+					if ($part !== '*') {
+						// Quote each of the parts
+						$part = $this->_identifier.$part.$this->_identifier;
+					}
+				}
+
+				$column = implode('.', $parts);
+
+			} else {
+				$column = $this->_identifier.$column.$this->_identifier;
+			}
+		}
+
+		if (isset($alias))
+			$column .= ' AS '.$this->_identifier.$alias.$this->_identifier;
+
 		return $column;
 	}
 
@@ -299,7 +352,7 @@ class Kohana_Database_DB2 extends Database {
 
 	public function table_prefix($schema=FALSE)
 	{
-		return ($schema === TRUE ? $this->_config['connection']['database'].'.' : '').$this->_config['table_prefix'];
+		return ($schema === TRUE ? $this->_config['connection']['schema'].'.' : '').$this->_config['table_prefix'];
 	}
 }
 ?>
diff --git a/config/database.php b/config/database.php
index aeb4ed4..d98efa7 100644
--- a/config/database.php
+++ b/config/database.php
@@ -23,6 +23,7 @@ return array
 			'password'   => '',
 			'persistent' => FALSE,
 			'database'   => '',
+			'schema'     => '',
 		),
 		'table_prefix' => '',
 		'charset'      => 'utf8',