3 files changed, 859 insertions, 574 deletions
diff --git a/phpBB/phpbb/db/tools/factory.php b/phpBB/phpbb/db/tools/factory.php
index 60db2ade03..24e2a4d875 100644
--- a/phpBB/phpbb/db/tools/factory.php
+++ b/phpBB/phpbb/db/tools/factory.php
@@ -25,7 +25,11 @@ class factory
 	 */
 	public function get($db_driver, $return_statements = false)
 	{
-		if ($db_driver instanceof \phpbb\db\driver\driver_interface)
+		if ($db_driver instanceof \phpbb\db\driver\mssql || $db_driver instanceof \phpbb\db\driver\mssql_base)
+		{
+			return new \phpbb\db\tools\mssql($db_driver, $return_statements);
+		}
+		else if ($db_driver instanceof \phpbb\db\driver\driver_interface)
 		{
 			return new \phpbb\db\tools\tools($db_driver, $return_statements);
 		}
diff --git a/phpBB/phpbb/db/tools/mssql.php b/phpBB/phpbb/db/tools/mssql.php
new file mode 100644
index 0000000000..b4a09143eb
--- /dev/null
+++ b/phpBB/phpbb/db/tools/mssql.php
@@ -0,0 +1,791 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\db\tools;
+
+/**
+* Database Tools for handling cross-db actions such as altering columns, etc.
+* Currently not supported is returning SQL for creating tables.
+*/
+class mssql extends tools
+{
+	/**
+	* Is the used MS SQL Server a SQL Server 2000?
+	* @var bool
+	*/
+	protected $is_sql_server_2000;
+
+	/**
+	* Get the column types for every database we support
+	*
+	* @return array
+	*/
+	public static function get_dbms_type_map()
+	{
+		return array(
+			'mssql'		=> array(
+				'INT:'		=> '[int]',
+				'BINT'		=> '[float]',
+				'UINT'		=> '[int]',
+				'UINT:'		=> '[int]',
+				'TINT:'		=> '[int]',
+				'USINT'		=> '[int]',
+				'BOOL'		=> '[int]',
+				'VCHAR'		=> '[varchar] (255)',
+				'VCHAR:'	=> '[varchar] (%d)',
+				'CHAR:'		=> '[char] (%d)',
+				'XSTEXT'	=> '[varchar] (1000)',
+				'STEXT'		=> '[varchar] (3000)',
+				'TEXT'		=> '[varchar] (8000)',
+				'MTEXT'		=> '[text]',
+				'XSTEXT_UNI'=> '[varchar] (100)',
+				'STEXT_UNI'	=> '[varchar] (255)',
+				'TEXT_UNI'	=> '[varchar] (4000)',
+				'MTEXT_UNI'	=> '[text]',
+				'TIMESTAMP'	=> '[int]',
+				'DECIMAL'	=> '[float]',
+				'DECIMAL:'	=> '[float]',
+				'PDECIMAL'	=> '[float]',
+				'PDECIMAL:'	=> '[float]',
+				'VCHAR_UNI'	=> '[varchar] (255)',
+				'VCHAR_UNI:'=> '[varchar] (%d)',
+				'VCHAR_CI'	=> '[varchar] (255)',
+				'VARBINARY'	=> '[varchar] (255)',
+			),
+
+			'mssqlnative'	=> array(
+				'INT:'		=> '[int]',
+				'BINT'		=> '[float]',
+				'UINT'		=> '[int]',
+				'UINT:'		=> '[int]',
+				'TINT:'		=> '[int]',
+				'USINT'		=> '[int]',
+				'BOOL'		=> '[int]',
+				'VCHAR'		=> '[varchar] (255)',
+				'VCHAR:'	=> '[varchar] (%d)',
+				'CHAR:'		=> '[char] (%d)',
+				'XSTEXT'	=> '[varchar] (1000)',
+				'STEXT'		=> '[varchar] (3000)',
+				'TEXT'		=> '[varchar] (8000)',
+				'MTEXT'		=> '[text]',
+				'XSTEXT_UNI'=> '[varchar] (100)',
+				'STEXT_UNI'	=> '[varchar] (255)',
+				'TEXT_UNI'	=> '[varchar] (4000)',
+				'MTEXT_UNI'	=> '[text]',
+				'TIMESTAMP'	=> '[int]',
+				'DECIMAL'	=> '[float]',
+				'DECIMAL:'	=> '[float]',
+				'PDECIMAL'	=> '[float]',
+				'PDECIMAL:'	=> '[float]',
+				'VCHAR_UNI'	=> '[varchar] (255)',
+				'VCHAR_UNI:'=> '[varchar] (%d)',
+				'VCHAR_CI'	=> '[varchar] (255)',
+				'VARBINARY'	=> '[varchar] (255)',
+			),
+		);
+	}
+
+	/**
+	* Constructor. Set DB Object and set {@link $return_statements return_statements}.
+	*
+	* @param \phpbb\db\driver\driver_interface	$db					Database connection
+	* @param bool		$return_statements	True if only statements should be returned and no SQL being executed
+	*/
+	public function __construct(\phpbb\db\driver\driver_interface $db, $return_statements = false)
+	{
+		parent::__construct($db, $return_statements);
+
+		// Determine mapping database type
+		switch ($this->db->get_sql_layer())
+		{
+			case 'mssql':
+			case 'mssql_odbc':
+				$this->sql_layer = 'mssql';
+			break;
+
+			case 'mssqlnative':
+				$this->sql_layer = 'mssqlnative';
+			break;
+		}
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_list_tables()
+	{
+		$sql = "SELECT name
+			FROM sysobjects
+			WHERE type='U'";
+		$result = $this->db->sql_query($sql);
+
+		$tables = array();
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$name = current($row);
+			$tables[$name] = $name;
+		}
+		$this->db->sql_freeresult($result);
+
+		return $tables;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_create_table($table_name, $table_data)
+	{
+		// holds the DDL for a column
+		$columns = $statements = array();
+
+		if ($this->sql_table_exists($table_name))
+		{
+			return $this->_sql_run_sql($statements);
+		}
+
+		// Begin transaction
+		$statements[] = 'begin';
+
+		// Determine if we have created a PRIMARY KEY in the earliest
+		$primary_key_gen = false;
+
+		// Determine if the table requires a sequence
+		$create_sequence = false;
+
+		// Begin table sql statement
+		$table_sql = 'CREATE TABLE [' . $table_name . '] (' . "\n";
+
+		if (!isset($table_data['PRIMARY_KEY']))
+		{
+			$table_data['COLUMNS']['mssqlindex'] = array('UINT', null, 'auto_increment');
+			$table_data['PRIMARY_KEY'] = 'mssqlindex';
+		}
+
+		// Iterate through the columns to create a table
+		foreach ($table_data['COLUMNS'] as $column_name => $column_data)
+		{
+			// here lies an array, filled with information compiled on the column's data
+			$prepared_column = $this->sql_prepare_column_data($table_name, $column_name, $column_data);
+
+			if (isset($prepared_column['auto_increment']) && $prepared_column['auto_increment'] && strlen($column_name) > 26) // "${column_name}_gen"
+			{
+				trigger_error("Index name '${column_name}_gen' on table '$table_name' is too long. The maximum auto increment column length is 26 characters.", E_USER_ERROR);
+			}
+
+			// here we add the definition of the new column to the list of columns
+			$columns[] = "\t [{$column_name}] " . $prepared_column['column_type_sql_default'];
+
+			// see if we have found a primary key set due to a column definition if we have found it, we can stop looking
+			if (!$primary_key_gen)
+			{
+				$primary_key_gen = isset($prepared_column['primary_key_set']) && $prepared_column['primary_key_set'];
+			}
+
+			// create sequence DDL based off of the existance of auto incrementing columns
+			if (!$create_sequence && isset($prepared_column['auto_increment']) && $prepared_column['auto_increment'])
+			{
+				$create_sequence = $column_name;
+			}
+		}
+
+		// this makes up all the columns in the create table statement
+		$table_sql .= implode(",\n", $columns);
+
+		// Close the table for two DBMS and add to the statements
+		$table_sql .= "\n);";
+		$statements[] = $table_sql;
+
+		// we have yet to create a primary key for this table,
+		// this means that we can add the one we really wanted instead
+		if (!$primary_key_gen)
+		{
+			// Write primary key
+			if (isset($table_data['PRIMARY_KEY']))
+			{
+				if (!is_array($table_data['PRIMARY_KEY']))
+				{
+					$table_data['PRIMARY_KEY'] = array($table_data['PRIMARY_KEY']);
+				}
+
+				// We need the data here
+				$old_return_statements = $this->return_statements;
+				$this->return_statements = true;
+
+				$primary_key_stmts = $this->sql_create_primary_key($table_name, $table_data['PRIMARY_KEY']);
+				foreach ($primary_key_stmts as $pk_stmt)
+				{
+					$statements[] = $pk_stmt;
+				}
+
+				$this->return_statements = $old_return_statements;
+			}
+		}
+
+		// Write Keys
+		if (isset($table_data['KEYS']))
+		{
+			foreach ($table_data['KEYS'] as $key_name => $key_data)
+			{
+				if (!is_array($key_data[1]))
+				{
+					$key_data[1] = array($key_data[1]);
+				}
+
+				$old_return_statements = $this->return_statements;
+				$this->return_statements = true;
+
+				$key_stmts = ($key_data[0] == 'UNIQUE') ? $this->sql_create_unique_index($table_name, $key_name, $key_data[1]) : $this->sql_create_index($table_name, $key_name, $key_data[1]);
+
+				foreach ($key_stmts as $key_stmt)
+				{
+					$statements[] = $key_stmt;
+				}
+
+				$this->return_statements = $old_return_statements;
+			}
+		}
+
+		// Commit Transaction
+		$statements[] = 'commit';
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_list_columns($table_name)
+	{
+		$columns = array();
+
+		$sql = "SELECT c.name
+			FROM syscolumns c
+			LEFT JOIN sysobjects o ON c.id = o.id
+			WHERE o.name = '{$table_name}'";
+		$result = $this->db->sql_query($sql);
+
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$column = strtolower(current($row));
+			$columns[$column] = $column;
+		}
+		$this->db->sql_freeresult($result);
+
+		return $columns;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_index_exists($table_name, $index_name)
+	{
+		$sql = "EXEC sp_statistics '$table_name'";
+		$result = $this->db->sql_query($sql);
+
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			if ($row['TYPE'] == 3)
+			{
+				if (strtolower($row['INDEX_NAME']) == strtolower($index_name))
+				{
+					$this->db->sql_freeresult($result);
+					return true;
+				}
+			}
+		}
+		$this->db->sql_freeresult($result);
+
+		return false;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_unique_index_exists($table_name, $index_name)
+	{
+		$sql = "EXEC sp_statistics '$table_name'";
+		$result = $this->db->sql_query($sql);
+
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			// Usually NON_UNIQUE is the column we want to check, but we allow for both
+			if ($row['TYPE'] == 3)
+			{
+				if (strtolower($row['INDEX_NAME']) == strtolower($index_name))
+				{
+					$this->db->sql_freeresult($result);
+					return true;
+				}
+			}
+		}
+		$this->db->sql_freeresult($result);
+
+		return false;
+	}
+
+	/**
+	 * {@inheritDoc}
+	*/
+	function sql_prepare_column_data($table_name, $column_name, $column_data)
+	{
+		if (strlen($column_name) > 30)
+		{
+			trigger_error("Column name '$column_name' on table '$table_name' is too long. The maximum is 30 characters.", E_USER_ERROR);
+		}
+
+		// Get type
+		list($column_type, $orig_column_type) = $this->get_column_type($column_data[0]);
+
+		// Adjust default value if db-dependent specified
+		if (is_array($column_data[1]))
+		{
+			$column_data[1] = (isset($column_data[1][$this->sql_layer])) ? $column_data[1][$this->sql_layer] : $column_data[1]['default'];
+		}
+
+		$sql = '';
+
+		$return_array = array();
+
+		$sql .= " {$column_type} ";
+		$sql_default = " {$column_type} ";
+
+		// For adding columns we need the default definition
+		if (!is_null($column_data[1]))
+		{
+			// For hexadecimal values do not use single quotes
+			if (strpos($column_data[1], '0x') === 0)
+			{
+				$return_array['default'] = 'DEFAULT (' . $column_data[1] . ') ';
+				$sql_default .= $return_array['default'];
+			}
+			else
+			{
+				$return_array['default'] = 'DEFAULT (' . ((is_numeric($column_data[1])) ? $column_data[1] : "'{$column_data[1]}'") . ') ';
+				$sql_default .= $return_array['default'];
+			}
+		}
+
+		if (isset($column_data[2]) && $column_data[2] == 'auto_increment')
+		{
+			// $sql .= 'IDENTITY (1, 1) ';
+			$sql_default .= 'IDENTITY (1, 1) ';
+		}
+
+		$return_array['textimage'] = $column_type === '[text]';
+
+		if (!is_null($column_data[1]) || (isset($column_data[2]) && $column_data[2] == 'auto_increment'))
+		{
+			$sql .= 'NOT NULL';
+			$sql_default .= 'NOT NULL';
+		}
+		else
+		{
+			$sql .= 'NULL';
+			$sql_default .= 'NULL';
+		}
+
+		$return_array['column_type_sql_default'] = $sql_default;
+
+		$return_array['column_type_sql'] = $sql;
+
+		return $return_array;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_column_add($table_name, $column_name, $column_data, $inline = false)
+	{
+		$column_data = $this->sql_prepare_column_data($table_name, $column_name, $column_data);
+		$statements = array();
+
+		// Does not support AFTER, only through temporary table
+		$statements[] = 'ALTER TABLE [' . $table_name . '] ADD [' . $column_name . '] ' . $column_data['column_type_sql_default'];
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_column_remove($table_name, $column_name, $inline = false)
+	{
+		$statements = array();
+
+		// We need the data here
+		$old_return_statements = $this->return_statements;
+		$this->return_statements = true;
+
+		$indexes = $this->get_existing_indexes($table_name, $column_name);
+		$indexes = array_merge($indexes, $this->get_existing_indexes($table_name, $column_name, true));
+
+		// Drop any indexes
+		$recreate_indexes = array();
+		if (!empty($indexes))
+		{
+			foreach ($indexes as $index_name => $index_data)
+			{
+				$result = $this->sql_index_drop($table_name, $index_name);
+				$statements = array_merge($statements, $result);
+				if (sizeof($index_data) > 1)
+				{
+					// Remove this column from the index and recreate it
+					$recreate_indexes[$index_name] = array_diff($index_data, array($column_name));
+				}
+			}
+		}
+
+		// Drop default value constraint
+		$result = $this->mssql_get_drop_default_constraints_queries($table_name, $column_name);
+		$statements = array_merge($statements, $result);
+
+		// Remove the column
+		$statements[] = 'ALTER TABLE [' . $table_name . '] DROP COLUMN [' . $column_name . ']';
+
+		if (!empty($recreate_indexes))
+		{
+			// Recreate indexes after we removed the column
+			foreach ($recreate_indexes as $index_name => $index_data)
+			{
+				$result = $this->sql_create_index($table_name, $index_name, $index_data);
+				$statements = array_merge($statements, $result);
+			}
+		}
+
+		$this->return_statements = $old_return_statements;
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_index_drop($table_name, $index_name)
+	{
+		$statements = array();
+
+		$statements[] = 'DROP INDEX ' . $table_name . '.' . $index_name;
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_table_drop($table_name)
+	{
+		$statements = array();
+
+		if (!$this->sql_table_exists($table_name))
+		{
+			return $this->_sql_run_sql($statements);
+		}
+
+		// the most basic operation, get rid of the table
+		$statements[] = 'DROP TABLE ' . $table_name;
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_create_primary_key($table_name, $column, $inline = false)
+	{
+		$statements = array();
+
+		$sql = "ALTER TABLE [{$table_name}] WITH NOCHECK ADD ";
+		$sql .= "CONSTRAINT [PK_{$table_name}] PRIMARY KEY  CLUSTERED (";
+		$sql .= '[' . implode("],\n\t\t[", $column) . ']';
+		$sql .= ')';
+
+		$statements[] = $sql;
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_create_unique_index($table_name, $index_name, $column)
+	{
+		$statements = array();
+
+		$this->check_index_name_length($table_name, $index_name);
+
+		$statements[] = 'CREATE UNIQUE INDEX [' . $index_name . '] ON [' . $table_name . ']([' . implode('], [', $column) . '])';
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_create_index($table_name, $index_name, $column)
+	{
+		$statements = array();
+
+		$this->check_index_name_length($table_name, $index_name);
+
+		// remove index length
+		$column = preg_replace('#:.*$#', '', $column);
+
+		$statements[] = 'CREATE INDEX [' . $index_name . '] ON [' . $table_name . ']([' . implode('], [', $column) . '])';
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_list_index($table_name)
+	{
+		$index_array = array();
+		$sql = "EXEC sp_statistics '$table_name'";
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			if ($row['TYPE'] == 3)
+			{
+				$index_array[] = strtolower($row['INDEX_NAME']);
+			}
+		}
+		$this->db->sql_freeresult($result);
+
+		return $index_array;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	function sql_column_change($table_name, $column_name, $column_data, $inline = false)
+	{
+		$column_data = $this->sql_prepare_column_data($table_name, $column_name, $column_data);
+		$statements = array();
+
+		// We need the data here
+		$old_return_statements = $this->return_statements;
+		$this->return_statements = true;
+
+		$indexes = $this->get_existing_indexes($table_name, $column_name);
+		$unique_indexes = $this->get_existing_indexes($table_name, $column_name, true);
+
+		// Drop any indexes
+		if (!empty($indexes) || !empty($unique_indexes))
+		{
+			$drop_indexes = array_merge(array_keys($indexes), array_keys($unique_indexes));
+			foreach ($drop_indexes as $index_name)
+			{
+				$result = $this->sql_index_drop($table_name, $index_name);
+				$statements = array_merge($statements, $result);
+			}
+		}
+
+		// Drop default value constraint
+		$result = $this->mssql_get_drop_default_constraints_queries($table_name, $column_name);
+		$statements = array_merge($statements, $result);
+
+		// Change the column
+		$statements[] = 'ALTER TABLE [' . $table_name . '] ALTER COLUMN [' . $column_name . '] ' . $column_data['column_type_sql'];
+
+		if (!empty($column_data['default']))
+		{
+			// Add new default value constraint
+			$statements[] = 'ALTER TABLE [' . $table_name . '] ADD CONSTRAINT [DF_' . $table_name . '_' . $column_name . '_1] ' . $this->db->sql_escape($column_data['default']) . ' FOR [' . $column_name . ']';
+		}
+
+		if (!empty($indexes))
+		{
+			// Recreate indexes after we changed the column
+			foreach ($indexes as $index_name => $index_data)
+			{
+				$result = $this->sql_create_index($table_name, $index_name, $index_data);
+				$statements = array_merge($statements, $result);
+			}
+		}
+
+		if (!empty($unique_indexes))
+		{
+			// Recreate unique indexes after we changed the column
+			foreach ($unique_indexes as $index_name => $index_data)
+			{
+				$result = $this->sql_create_unique_index($table_name, $index_name, $index_data);
+				$statements = array_merge($statements, $result);
+			}
+		}
+
+		$this->return_statements = $old_return_statements;
+
+		return $this->_sql_run_sql($statements);
+	}
+
+	/**
+	* Get queries to drop the default constraints of a column
+	*
+	* We need to drop the default constraints of a column,
+	* before being able to change their type or deleting them.
+	*
+	* @param string $table_name
+	* @param string $column_name
+	* @return array		Array with SQL statements
+	*/
+	protected function mssql_get_drop_default_constraints_queries($table_name, $column_name)
+	{
+		$statements = array();
+		if ($this->mssql_is_sql_server_2000())
+		{
+			// http://msdn.microsoft.com/en-us/library/aa175912%28v=sql.80%29.aspx
+			// Deprecated in SQL Server 2005
+			$sql = "SELECT so.name AS def_name
+				FROM sysobjects so
+				JOIN sysconstraints sc ON so.id = sc.constid
+				WHERE object_name(so.parent_obj) = '{$table_name}'
+					AND so.xtype = 'D'
+					AND sc.colid = (SELECT colid FROM syscolumns
+						WHERE id = object_id('{$table_name}')
+							AND name = '{$column_name}')";
+		}
+		else
+		{
+			$sql = "SELECT dobj.name AS def_name
+				FROM sys.columns col
+					LEFT OUTER JOIN sys.objects dobj ON (dobj.object_id = col.default_object_id AND dobj.type = 'D')
+				WHERE col.object_id = object_id('{$table_name}')
+					AND col.name = '{$column_name}'
+					AND dobj.name IS NOT NULL";
+		}
+
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$statements[] = 'ALTER TABLE [' . $table_name . '] DROP CONSTRAINT [' . $row['def_name'] . ']';
+		}
+		$this->db->sql_freeresult($result);
+
+		return $statements;
+	}
+
+	/**
+	* Get a list with existing indexes for the column
+	*
+	* @param string $table_name
+	* @param string $column_name
+	* @param bool $unique Should we get unique indexes or normal ones
+	* @return array		Array with Index name => columns
+	*/
+	public function get_existing_indexes($table_name, $column_name, $unique = false)
+	{
+		$existing_indexes = array();
+		if ($this->mssql_is_sql_server_2000())
+		{
+			// http://msdn.microsoft.com/en-us/library/aa175912%28v=sql.80%29.aspx
+			// Deprecated in SQL Server 2005
+			$sql = "SELECT DISTINCT ix.name AS phpbb_index_name
+				FROM sysindexes ix
+				INNER JOIN sysindexkeys ixc
+					ON ixc.id = ix.id
+						AND ixc.indid = ix.indid
+				INNER JOIN syscolumns cols
+					ON cols.colid = ixc.colid
+						AND cols.id = ix.id
+				WHERE ix.id = object_id('{$table_name}')
+					AND cols.name = '{$column_name}'
+					AND INDEXPROPERTY(ix.id, ix.name, 'IsUnique') = " . ($unique ? '1' : '0');
+		}
+		else
+		{
+			$sql = "SELECT DISTINCT ix.name AS phpbb_index_name
+				FROM sys.indexes ix
+				INNER JOIN sys.index_columns ixc
+					ON ixc.object_id = ix.object_id
+						AND ixc.index_id = ix.index_id
+				INNER JOIN sys.columns cols
+					ON cols.column_id = ixc.column_id
+						AND cols.object_id = ix.object_id
+				WHERE ix.object_id = object_id('{$table_name}')
+					AND cols.name = '{$column_name}'
+					AND ix.is_unique = " . ($unique ? '1' : '0');
+		}
+
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			if (!isset($row['is_unique']) || ($unique && $row['is_unique'] == 'UNIQUE') || (!$unique && $row['is_unique'] == 'NONUNIQUE'))
+			{
+				$existing_indexes[$row['phpbb_index_name']] = array();
+			}
+		}
+		$this->db->sql_freeresult($result);
+
+		if (empty($existing_indexes))
+		{
+			return array();
+		}
+
+		if ($this->mssql_is_sql_server_2000())
+		{
+			$sql = "SELECT DISTINCT ix.name AS phpbb_index_name, cols.name AS phpbb_column_name
+				FROM sysindexes ix
+				INNER JOIN sysindexkeys ixc
+					ON ixc.id = ix.id
+						AND ixc.indid = ix.indid
+				INNER JOIN syscolumns cols
+					ON cols.colid = ixc.colid
+						AND cols.id = ix.id
+				WHERE ix.id = object_id('{$table_name}')
+					AND " . $this->db->sql_in_set('ix.name', array_keys($existing_indexes));
+		}
+		else
+		{
+			$sql = "SELECT DISTINCT ix.name AS phpbb_index_name, cols.name AS phpbb_column_name
+				FROM sys.indexes ix
+				INNER JOIN sys.index_columns ixc
+					ON ixc.object_id = ix.object_id
+						AND ixc.index_id = ix.index_id
+				INNER JOIN sys.columns cols
+					ON cols.column_id = ixc.column_id
+						AND cols.object_id = ix.object_id
+				WHERE ix.object_id = object_id('{$table_name}')
+					AND " . $this->db->sql_in_set('ix.name', array_keys($existing_indexes));
+		}
+
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$existing_indexes[$row['phpbb_index_name']][] = $row['phpbb_column_name'];
+		}
+		$this->db->sql_freeresult($result);
+
+		return $existing_indexes;
+	}
+
+	/**
+	* Is the used MS SQL Server a SQL Server 2000?
+	*
+	* @return bool
+	*/
+	protected function mssql_is_sql_server_2000()
+	{
+		if ($this->is_sql_server_2000 === null)
+		{
+			$sql = "SELECT CAST(SERVERPROPERTY('productversion') AS VARCHAR(25)) AS mssql_version";
+			$result = $this->db->sql_query($sql);
+			$properties = $this->db->sql_fetchrow($result);
+			$this->db->sql_freeresult($result);
+			$this->is_sql_server_2000 = $properties['mssql_version'][0] == '8';
+		}
+
+		return $this->is_sql_server_2000;
+	}
+
+}
diff --git a/phpBB/phpbb/db/tools/tools.php b/phpBB/phpbb/db/tools/tools.php
index 152ec6b00f..f05c690e5f 100644
--- a/phpBB/phpbb/db/tools/tools.php
+++ b/phpBB/phpbb/db/tools/tools.php
@@ -36,12 +36,6 @@ class tools implements tools_interface
 	var $dbms_type_map = array();
 
 	/**
-	* Is the used MS SQL Server a SQL Server 2000?
-	* @var bool
-	*/
-	protected $is_sql_server_2000;
-
-	/**
 	* Get the column types for every database we support
 	*
 	* @return array
@@ -109,66 +103,6 @@ class tools implements tools_interface
 				'VARBINARY'	=> 'varbinary(255)',
 			),
 
-			'mssql'		=> array(
-				'INT:'		=> '[int]',
-				'BINT'		=> '[float]',
-				'UINT'		=> '[int]',
-				'UINT:'		=> '[int]',
-				'TINT:'		=> '[int]',
-				'USINT'		=> '[int]',
-				'BOOL'		=> '[int]',
-				'VCHAR'		=> '[varchar] (255)',
-				'VCHAR:'	=> '[varchar] (%d)',
-				'CHAR:'		=> '[char] (%d)',
-				'XSTEXT'	=> '[varchar] (1000)',
-				'STEXT'		=> '[varchar] (3000)',
-				'TEXT'		=> '[varchar] (8000)',
-				'MTEXT'		=> '[text]',
-				'XSTEXT_UNI'=> '[varchar] (100)',
-				'STEXT_UNI'	=> '[varchar] (255)',
-				'TEXT_UNI'	=> '[varchar] (4000)',
-				'MTEXT_UNI'	=> '[text]',
-				'TIMESTAMP'	=> '[int]',
-				'DECIMAL'	=> '[float]',
-				'DECIMAL:'	=> '[float]',
-				'PDECIMAL'	=> '[float]',
-				'PDECIMAL:'	=> '[float]',
-				'VCHAR_UNI'	=> '[varchar] (255)',
-				'VCHAR_UNI:'=> '[varchar] (%d)',
-				'VCHAR_CI'	=> '[varchar] (255)',
-				'VARBINARY'	=> '[varchar] (255)',
-			),
-
-			'mssqlnative'	=> array(
-				'INT:'		=> '[int]',
-				'BINT'		=> '[float]',
-				'UINT'		=> '[int]',
-				'UINT:'		=> '[int]',
-				'TINT:'		=> '[int]',
-				'USINT'		=> '[int]',
-				'BOOL'		=> '[int]',
-				'VCHAR'		=> '[varchar] (255)',
-				'VCHAR:'	=> '[varchar] (%d)',
-				'CHAR:'		=> '[char] (%d)',
-				'XSTEXT'	=> '[varchar] (1000)',
-				'STEXT'		=> '[varchar] (3000)',
-				'TEXT'		=> '[varchar] (8000)',
-				'MTEXT'		=> '[text]',
-				'XSTEXT_UNI'=> '[varchar] (100)',
-				'STEXT_UNI'	=> '[varchar] (255)',
-				'TEXT_UNI'	=> '[varchar] (4000)',
-				'MTEXT_UNI'	=> '[text]',
-				'TIMESTAMP'	=> '[int]',
-				'DECIMAL'	=> '[float]',
-				'DECIMAL:'	=> '[float]',
-				'PDECIMAL'	=> '[float]',
-				'PDECIMAL:'	=> '[float]',
-				'VCHAR_UNI'	=> '[varchar] (255)',
-				'VCHAR_UNI:'=> '[varchar] (%d)',
-				'VCHAR_CI'	=> '[varchar] (255)',
-				'VARBINARY'	=> '[varchar] (255)',
-			),
-
 			'oracle'	=> array(
 				'INT:'		=> 'number(%d)',
 				'BINT'		=> 'number(20)',
@@ -298,12 +232,6 @@ class tools implements tools_interface
 	var $unsigned_types = array('UINT', 'UINT:', 'USINT', 'BOOL', 'TIMESTAMP');
 
 	/**
-	* A list of supported DBMS. We change this class to support more DBMS, the DBMS itself only need to follow some rules.
-	* @var array
-	*/
-	var $supported_dbms = array('mssql', 'mssqlnative', 'mysql_40', 'mysql_41', 'oracle', 'postgres', 'sqlite', 'sqlite3');
-
-	/**
 	* This is set to true if user only wants to return the 'to-be-executed' SQL statement(s) (as an array).
 	* This mode has no effect on some methods (inserting of data for example). This is expressed within the methods command.
 	*/
@@ -344,15 +272,6 @@ class tools implements tools_interface
 				$this->sql_layer = 'mysql_41';
 			break;
 
-			case 'mssql':
-			case 'mssql_odbc':
-				$this->sql_layer = 'mssql';
-			break;
-
-			case 'mssqlnative':
-				$this->sql_layer = 'mssqlnative';
-			break;
-
 			default:
 				$this->sql_layer = $this->db->get_sql_layer();
 			break;
@@ -396,14 +315,6 @@ class tools implements tools_interface
 						AND name <> "sqlite_sequence"';
 			break;
 
-			case 'mssql':
-			case 'mssql_odbc':
-			case 'mssqlnative':
-				$sql = "SELECT name
-					FROM sysobjects
-					WHERE type='U'";
-			break;
-
 			case 'postgres':
 				$sql = 'SELECT relname
 					FROM pg_stat_user_tables';
@@ -469,26 +380,7 @@ class tools implements tools_interface
 		$create_sequence = false;
 
 		// Begin table sql statement
-		switch ($this->sql_layer)
-		{
-			case 'mssql':
-			case 'mssqlnative':
-				$table_sql = 'CREATE TABLE [' . $table_name . '] (' . "\n";
-			break;
-
-			default:
-				$table_sql = 'CREATE TABLE ' . $table_name . ' (' . "\n";
-			break;
-		}
-
-		if ($this->sql_layer == 'mssql' || $this->sql_layer == 'mssqlnative')
-		{
-			if (!isset($table_data['PRIMARY_KEY']))
-			{
-				$table_data['COLUMNS']['mssqlindex'] = array('UINT', null, 'auto_increment');
-				$table_data['PRIMARY_KEY'] = 'mssqlindex';
-			}
-		}
+		$table_sql = 'CREATE TABLE ' . $table_name . ' (' . "\n";
 
 		// Iterate through the columns to create a table
 		foreach ($table_data['COLUMNS'] as $column_name => $column_data)
@@ -502,17 +394,7 @@ class tools implements tools_interface
 			}
 
 			// here we add the definition of the new column to the list of columns
-			switch ($this->sql_layer)
-			{
-				case 'mssql':
-				case 'mssqlnative':
-					$columns[] = "\t [{$column_name}] " . $prepared_column['column_type_sql_default'];
-				break;
-
-				default:
-					$columns[] = "\t {$column_name} " . $prepared_column['column_type_sql'];
-				break;
-			}
+			$columns[] = "\t {$column_name} " . $prepared_column['column_type_sql'];
 
 			// see if we have found a primary key set due to a column definition if we have found it, we can stop looking
 			if (!$primary_key_gen)
@@ -530,16 +412,6 @@ class tools implements tools_interface
 		// this makes up all the columns in the create table statement
 		$table_sql .= implode(",\n", $columns);
 
-		// Close the table for two DBMS and add to the statements
-		switch ($this->sql_layer)
-		{
-			case 'mssql':
-			case 'mssqlnative':
-				$table_sql .= "\n);";
-				$statements[] = $table_sql;
-			break;
-		}
-
 		// we have yet to create a primary key for this table,
 		// this means that we can add the one we really wanted instead
 		if (!$primary_key_gen)
@@ -562,21 +434,6 @@ class tools implements tools_interface
 						$table_sql .= ",\n\t PRIMARY KEY (" . implode(', ', $table_data['PRIMARY_KEY']) . ')';
 					break;
 
-					case 'mssql':
-					case 'mssqlnative':
-						// We need the data here
-						$old_return_statements = $this->return_statements;
-						$this->return_statements = true;
-
-						$primary_key_stmts = $this->sql_create_primary_key($table_name, $table_data['PRIMARY_KEY']);
-						foreach ($primary_key_stmts as $pk_stmt)
-						{
-							$statements[] = $pk_stmt;
-						}
-
-						$this->return_statements = $old_return_statements;
-					break;
-
 					case 'oracle':
 						$table_sql .= ",\n\t CONSTRAINT pk_{$table_name} PRIMARY KEY (" . implode(', ', $table_data['PRIMARY_KEY']) . ')';
 					break;
@@ -1073,16 +930,6 @@ class tools implements tools_interface
 						AND a.attrelid = c.oid";
 			break;
 
-			// same deal with PostgreSQL, we must perform more complex operations than
-			// we technically could
-			case 'mssql':
-			case 'mssqlnative':
-				$sql = "SELECT c.name
-					FROM syscolumns c
-					LEFT JOIN sysobjects o ON c.id = o.id
-					WHERE o.name = '{$table_name}'";
-			break;
-
 			case 'oracle':
 				$sql = "SELECT column_name
 					FROM user_tab_columns
@@ -1154,27 +1001,6 @@ class tools implements tools_interface
 	 */
 	function sql_index_exists($table_name, $index_name)
 	{
-		if ($this->sql_layer == 'mssql' || $this->sql_layer == 'mssqlnative')
-		{
-			$sql = "EXEC sp_statistics '$table_name'";
-			$result = $this->db->sql_query($sql);
-
-			while ($row = $this->db->sql_fetchrow($result))
-			{
-				if ($row['TYPE'] == 3)
-				{
-					if (strtolower($row['INDEX_NAME']) == strtolower($index_name))
-					{
-						$this->db->sql_freeresult($result);
-						return true;
-					}
-				}
-			}
-			$this->db->sql_freeresult($result);
-
-			return false;
-		}
-
 		switch ($this->sql_layer)
 		{
 			case 'postgres':
@@ -1246,27 +1072,6 @@ class tools implements tools_interface
 	 */
 	function sql_unique_index_exists($table_name, $index_name)
 	{
-		if ($this->sql_layer == 'mssql' || $this->sql_layer == 'mssqlnative')
-		{
-			$sql = "EXEC sp_statistics '$table_name'";
-			$result = $this->db->sql_query($sql);
-
-			while ($row = $this->db->sql_fetchrow($result))
-			{
-				// Usually NON_UNIQUE is the column we want to check, but we allow for both
-				if ($row['TYPE'] == 3)
-				{
-					if (strtolower($row['INDEX_NAME']) == strtolower($index_name))
-					{
-						$this->db->sql_freeresult($result);
-						return true;
-					}
-				}
-			}
-			$this->db->sql_freeresult($result);
-			return false;
-		}
-
 		switch ($this->sql_layer)
 		{
 			case 'postgres':
@@ -1410,50 +1215,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				$sql .= " {$column_type} ";
-				$sql_default = " {$column_type} ";
-
-				// For adding columns we need the default definition
-				if (!is_null($column_data[1]))
-				{
-					// For hexadecimal values do not use single quotes
-					if (strpos($column_data[1], '0x') === 0)
-					{
-						$return_array['default'] = 'DEFAULT (' . $column_data[1] . ') ';
-						$sql_default .= $return_array['default'];
-					}
-					else
-					{
-						$return_array['default'] = 'DEFAULT (' . ((is_numeric($column_data[1])) ? $column_data[1] : "'{$column_data[1]}'") . ') ';
-						$sql_default .= $return_array['default'];
-					}
-				}
-
-				if (isset($column_data[2]) && $column_data[2] == 'auto_increment')
-				{
-//					$sql .= 'IDENTITY (1, 1) ';
-					$sql_default .= 'IDENTITY (1, 1) ';
-				}
-
-				$return_array['textimage'] = $column_type === '[text]';
-
-				if (!is_null($column_data[1]) || (isset($column_data[2]) && $column_data[2] == 'auto_increment'))
-				{
-					$sql .= 'NOT NULL';
-					$sql_default .= 'NOT NULL';
-				}
-				else
-				{
-					$sql .= 'NULL';
-					$sql_default .= 'NULL';
-				}
-
-				$return_array['column_type_sql_default'] = $sql_default;
-
-			break;
-
 			case 'mysql_40':
 			case 'mysql_41':
 				$sql .= " {$column_type} ";
@@ -1653,12 +1414,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				// Does not support AFTER, only through temporary table
-				$statements[] = 'ALTER TABLE [' . $table_name . '] ADD [' . $column_name . '] ' . $column_data['column_type_sql_default'];
-			break;
-
 			case 'mysql_40':
 			case 'mysql_41':
 				$after = (!empty($column_data['after'])) ? ' AFTER ' . $column_data['after'] : '';
@@ -1770,51 +1525,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				// We need the data here
-				$old_return_statements = $this->return_statements;
-				$this->return_statements = true;
-
-				$indexes = $this->get_existing_indexes($table_name, $column_name);
-				$indexes = array_merge($indexes, $this->get_existing_indexes($table_name, $column_name, true));
-
-				// Drop any indexes
-				$recreate_indexes = array();
-				if (!empty($indexes))
-				{
-					foreach ($indexes as $index_name => $index_data)
-					{
-						$result = $this->sql_index_drop($table_name, $index_name);
-						$statements = array_merge($statements, $result);
-						if (sizeof($index_data) > 1)
-						{
-							// Remove this column from the index and recreate it
-							$recreate_indexes[$index_name] = array_diff($index_data, array($column_name));
-						}
-					}
-				}
-
-				// Drop default value constraint
-				$result = $this->mssql_get_drop_default_constraints_queries($table_name, $column_name);
-				$statements = array_merge($statements, $result);
-
-				// Remove the column
-				$statements[] = 'ALTER TABLE [' . $table_name . '] DROP COLUMN [' . $column_name . ']';
-
-				if (!empty($recreate_indexes))
-				{
-					// Recreate indexes after we removed the column
-					foreach ($recreate_indexes as $index_name => $index_data)
-					{
-						$result = $this->sql_create_index($table_name, $index_name, $index_data);
-						$statements = array_merge($statements, $result);
-					}
-				}
-
-				$this->return_statements = $old_return_statements;
-			break;
-
 			case 'mysql_40':
 			case 'mysql_41':
 				$statements[] = 'ALTER TABLE `' . $table_name . '` DROP COLUMN `' . $column_name . '`';
@@ -1899,11 +1609,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				$statements[] = 'DROP INDEX ' . $table_name . '.' . $index_name;
-			break;
-
 			case 'mysql_40':
 			case 'mysql_41':
 				$statements[] = 'DROP INDEX ' . $index_name . ' ON ' . $table_name;
@@ -1988,16 +1693,6 @@ class tools implements tools_interface
 				$statements[] = 'ALTER TABLE ' . $table_name . ' ADD PRIMARY KEY (' . implode(', ', $column) . ')';
 			break;
 
-			case 'mssql':
-			case 'mssqlnative':
-				$sql = "ALTER TABLE [{$table_name}] WITH NOCHECK ADD ";
-				$sql .= "CONSTRAINT [PK_{$table_name}] PRIMARY KEY  CLUSTERED (";
-				$sql .= '[' . implode("],\n\t\t[", $column) . ']';
-				$sql .= ')';
-
-				$statements[] = $sql;
-			break;
-
 			case 'oracle':
 				$statements[] = 'ALTER TABLE ' . $table_name . ' add CONSTRAINT pk_' . $table_name . ' PRIMARY KEY (' . implode(', ', $column) . ')';
 			break;
@@ -2064,12 +1759,7 @@ class tools implements tools_interface
 	{
 		$statements = array();
 
-		$table_prefix = substr(CONFIG_TABLE, 0, -6); // strlen(config)
-		if (strlen($table_name . '_' . $index_name) - strlen($table_prefix) > 24)
-		{
-			$max_length = strlen($table_prefix) + 24;
-			trigger_error("Index name '{$table_name}_$index_name' on table '$table_name' is too long. The maximum is $max_length characters.", E_USER_ERROR);
-		}
+		$this->check_index_name_length($table_name, $index_name);
 
 		switch ($this->sql_layer)
 		{
@@ -2084,11 +1774,6 @@ class tools implements tools_interface
 			case 'mysql_41':
 				$statements[] = 'ALTER TABLE ' . $table_name . ' ADD UNIQUE INDEX ' . $index_name . '(' . implode(', ', $column) . ')';
 			break;
-
-			case 'mssql':
-			case 'mssqlnative':
-				$statements[] = 'CREATE UNIQUE INDEX [' . $index_name . '] ON [' . $table_name . ']([' . implode('], [', $column) . '])';
-			break;
 		}
 
 		return $this->_sql_run_sql($statements);
@@ -2101,12 +1786,7 @@ class tools implements tools_interface
 	{
 		$statements = array();
 
-		$table_prefix = substr(CONFIG_TABLE, 0, -6); // strlen(config)
-		if (strlen($table_name . $index_name) - strlen($table_prefix) > 24)
-		{
-			$max_length = strlen($table_prefix) + 24;
-			trigger_error("Index name '{$table_name}_$index_name' on table '$table_name' is too long. The maximum is $max_length characters.", E_USER_ERROR);
-		}
+		$this->check_index_name_length($table_name, $index_name);
 
 		// remove index length unless MySQL4
 		if ('mysql_40' != $this->sql_layer)
@@ -2137,96 +1817,91 @@ class tools implements tools_interface
 			case 'mysql_41':
 				$statements[] = 'ALTER TABLE ' . $table_name . ' ADD INDEX ' . $index_name . ' (' . implode(', ', $column) . ')';
 			break;
-
-			case 'mssql':
-			case 'mssqlnative':
-				$statements[] = 'CREATE INDEX [' . $index_name . '] ON [' . $table_name . ']([' . implode('], [', $column) . '])';
-			break;
 		}
 
 		return $this->_sql_run_sql($statements);
 	}
 
 	/**
+	 * Check whether the index name is too long
+	 *
+	 * @param string $table_name
+	 * @param string $index_name
+	 */
+	protected function check_index_name_length($table_name, $index_name)
+	{
+		$table_prefix = substr(CONFIG_TABLE, 0, -6); // strlen(config)
+		if (strlen($table_name . $index_name) - strlen($table_prefix) > 24)
+		{
+			$max_length = strlen($table_prefix) + 24;
+			trigger_error("Index name '{$table_name}_$index_name' on table '$table_name' is too long. The maximum is $max_length characters.", E_USER_ERROR);
+		}
+	}
+
+	/**
 	 * {@inheritDoc}
 	 */
 	function sql_list_index($table_name)
 	{
 		$index_array = array();
 
-		if ($this->sql_layer == 'mssql' || $this->sql_layer == 'mssqlnative')
-		{
-			$sql = "EXEC sp_statistics '$table_name'";
-			$result = $this->db->sql_query($sql);
-			while ($row = $this->db->sql_fetchrow($result))
-			{
-				if ($row['TYPE'] == 3)
-				{
-					$index_array[] = $row['INDEX_NAME'];
-				}
-			}
-			$this->db->sql_freeresult($result);
-		}
-		else
+		switch ($this->sql_layer)
 		{
-			switch ($this->sql_layer)
-			{
-				case 'postgres':
-					$sql = "SELECT ic.relname as index_name
-						FROM pg_class bc, pg_class ic, pg_index i
-						WHERE (bc.oid = i.indrelid)
-							AND (ic.oid = i.indexrelid)
-							AND (bc.relname = '" . $table_name . "')
-							AND (i.indisunique != 't')
-							AND (i.indisprimary != 't')";
-					$col = 'index_name';
+			case 'postgres':
+				$sql = "SELECT ic.relname as index_name
+					FROM pg_class bc, pg_class ic, pg_index i
+					WHERE (bc.oid = i.indrelid)
+						AND (ic.oid = i.indexrelid)
+						AND (bc.relname = '" . $table_name . "')
+						AND (i.indisunique != 't')
+						AND (i.indisprimary != 't')";
+				$col = 'index_name';
 				break;
 
-				case 'mysql_40':
-				case 'mysql_41':
-					$sql = 'SHOW KEYS
-						FROM ' . $table_name;
-					$col = 'Key_name';
+			case 'mysql_40':
+			case 'mysql_41':
+				$sql = 'SHOW KEYS
+					FROM ' . $table_name;
+				$col = 'Key_name';
 				break;
 
-				case 'oracle':
-					$sql = "SELECT index_name
-						FROM user_indexes
-						WHERE table_name = '" . strtoupper($table_name) . "'
-							AND generated = 'N'
-							AND uniqueness = 'NONUNIQUE'";
-					$col = 'index_name';
+			case 'oracle':
+				$sql = "SELECT index_name
+					FROM user_indexes
+					WHERE table_name = '" . strtoupper($table_name) . "'
+						AND generated = 'N'
+						AND uniqueness = 'NONUNIQUE'";
+				$col = 'index_name';
 				break;
 
-				case 'sqlite':
-				case 'sqlite3':
-					$sql = "PRAGMA index_info('" . $table_name . "');";
-					$col = 'name';
+			case 'sqlite':
+			case 'sqlite3':
+				$sql = "PRAGMA index_info('" . $table_name . "');";
+				$col = 'name';
 				break;
-			}
+		}
 
-			$result = $this->db->sql_query($sql);
-			while ($row = $this->db->sql_fetchrow($result))
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			if (($this->sql_layer == 'mysql_40' || $this->sql_layer == 'mysql_41') && !$row['Non_unique'])
 			{
-				if (($this->sql_layer == 'mysql_40' || $this->sql_layer == 'mysql_41') && !$row['Non_unique'])
-				{
-					continue;
-				}
+				continue;
+			}
 
-				switch ($this->sql_layer)
-				{
-					case 'oracle':
-					case 'postgres':
-					case 'sqlite':
-					case 'sqlite3':
-						$row[$col] = substr($row[$col], strlen($table_name) + 1);
+			switch ($this->sql_layer)
+			{
+				case 'oracle':
+				case 'postgres':
+				case 'sqlite':
+				case 'sqlite3':
+					$row[$col] = substr($row[$col], strlen($table_name) + 1);
 					break;
-				}
-
-				$index_array[] = $row[$col];
 			}
-			$this->db->sql_freeresult($result);
+
+			$index_array[] = $row[$col];
 		}
+		$this->db->sql_freeresult($result);
 
 		return array_map('strtolower', $index_array);
 	}
@@ -2254,62 +1929,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				// We need the data here
-				$old_return_statements = $this->return_statements;
-				$this->return_statements = true;
-
-				$indexes = $this->get_existing_indexes($table_name, $column_name);
-				$unique_indexes = $this->get_existing_indexes($table_name, $column_name, true);
-
-				// Drop any indexes
-				if (!empty($indexes) || !empty($unique_indexes))
-				{
-					$drop_indexes = array_merge(array_keys($indexes), array_keys($unique_indexes));
-					foreach ($drop_indexes as $index_name)
-					{
-						$result = $this->sql_index_drop($table_name, $index_name);
-						$statements = array_merge($statements, $result);
-					}
-				}
-
-				// Drop default value constraint
-				$result = $this->mssql_get_drop_default_constraints_queries($table_name, $column_name);
-				$statements = array_merge($statements, $result);
-
-				// Change the column
-				$statements[] = 'ALTER TABLE [' . $table_name . '] ALTER COLUMN [' . $column_name . '] ' . $column_data['column_type_sql'];
-
-				if (!empty($column_data['default']))
-				{
-					// Add new default value constraint
-					$statements[] = 'ALTER TABLE [' . $table_name . '] ADD CONSTRAINT [DF_' . $table_name . '_' . $column_name . '_1] ' . $this->db->sql_escape($column_data['default']) . ' FOR [' . $column_name . ']';
-				}
-
-				if (!empty($indexes))
-				{
-					// Recreate indexes after we changed the column
-					foreach ($indexes as $index_name => $index_data)
-					{
-						$result = $this->sql_create_index($table_name, $index_name, $index_data);
-						$statements = array_merge($statements, $result);
-					}
-				}
-
-				if (!empty($unique_indexes))
-				{
-					// Recreate unique indexes after we changed the column
-					foreach ($unique_indexes as $index_name => $index_data)
-					{
-						$result = $this->sql_create_unique_index($table_name, $index_name, $index_data);
-						$statements = array_merge($statements, $result);
-					}
-				}
-
-				$this->return_statements = $old_return_statements;
-			break;
-
 			case 'mysql_40':
 			case 'mysql_41':
 				$statements[] = 'ALTER TABLE `' . $table_name . '` CHANGE `' . $column_name . '` `' . $column_name . '` ' . $column_data['column_type_sql'];
@@ -2512,52 +2131,6 @@ class tools implements tools_interface
 	}
 
 	/**
-	* Get queries to drop the default constraints of a column
-	*
-	* We need to drop the default constraints of a column,
-	* before being able to change their type or deleting them.
-	*
-	* @param string $table_name
-	* @param string $column_name
-	* @return array		Array with SQL statements
-	*/
-	protected function mssql_get_drop_default_constraints_queries($table_name, $column_name)
-	{
-		$statements = array();
-		if ($this->mssql_is_sql_server_2000())
-		{
-			// http://msdn.microsoft.com/en-us/library/aa175912%28v=sql.80%29.aspx
-			// Deprecated in SQL Server 2005
-			$sql = "SELECT so.name AS def_name
-				FROM sysobjects so
-				JOIN sysconstraints sc ON so.id = sc.constid
-				WHERE object_name(so.parent_obj) = '{$table_name}'
-					AND so.xtype = 'D'
-					AND sc.colid = (SELECT colid FROM syscolumns
-						WHERE id = object_id('{$table_name}')
-							AND name = '{$column_name}')";
-		}
-		else
-		{
-			$sql = "SELECT dobj.name AS def_name
-				FROM sys.columns col
-					LEFT OUTER JOIN sys.objects dobj ON (dobj.object_id = col.default_object_id AND dobj.type = 'D')
-				WHERE col.object_id = object_id('{$table_name}')
-					AND col.name = '{$column_name}'
-					AND dobj.name IS NOT NULL";
-		}
-
-		$result = $this->db->sql_query($sql);
-		while ($row = $this->db->sql_fetchrow($result))
-		{
-			$statements[] = 'ALTER TABLE [' . $table_name . '] DROP CONSTRAINT [' . $row['def_name'] . ']';
-		}
-		$this->db->sql_freeresult($result);
-
-		return $statements;
-	}
-
-	/**
 	* Get a list with existing indexes for the column
 	*
 	* @param string $table_name
@@ -2584,40 +2157,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				if ($this->mssql_is_sql_server_2000())
-				{
-					// http://msdn.microsoft.com/en-us/library/aa175912%28v=sql.80%29.aspx
-					// Deprecated in SQL Server 2005
-					$sql = "SELECT DISTINCT ix.name AS phpbb_index_name
-					FROM sysindexes ix
-					INNER JOIN sysindexkeys ixc
-						ON ixc.id = ix.id
-							AND ixc.indid = ix.indid
-					INNER JOIN syscolumns cols
-						ON cols.colid = ixc.colid
-							AND cols.id = ix.id
-					WHERE ix.id = object_id('{$table_name}')
-						AND cols.name = '{$column_name}'
-						AND INDEXPROPERTY(ix.id, ix.name, 'IsUnique') = " . ($unique ? '1' : '0');
-				}
-				else
-				{
-					$sql = "SELECT DISTINCT ix.name AS phpbb_index_name
-					FROM sys.indexes ix
-					INNER JOIN sys.index_columns ixc
-						ON ixc.object_id = ix.object_id
-							AND ixc.index_id = ix.index_id
-					INNER JOIN sys.columns cols
-						ON cols.column_id = ixc.column_id
-							AND cols.object_id = ix.object_id
-					WHERE ix.object_id = object_id('{$table_name}')
-						AND cols.name = '{$column_name}'
-						AND ix.is_unique = " . ($unique ? '1' : '0');
-				}
-			break;
-
 			case 'oracle':
 				$sql = "SELECT ix.index_name  AS phpbb_index_name, ix.uniqueness AS is_unique
 					FROM all_ind_columns ixc, all_indexes ix
@@ -2644,36 +2183,6 @@ class tools implements tools_interface
 
 		switch ($this->sql_layer)
 		{
-			case 'mssql':
-			case 'mssqlnative':
-				if ($this->mssql_is_sql_server_2000())
-				{
-					$sql = "SELECT DISTINCT ix.name AS phpbb_index_name, cols.name AS phpbb_column_name
-						FROM sysindexes ix
-						INNER JOIN sysindexkeys ixc
-							ON ixc.id = ix.id
-								AND ixc.indid = ix.indid
-						INNER JOIN syscolumns cols
-							ON cols.colid = ixc.colid
-								AND cols.id = ix.id
-						WHERE ix.id = object_id('{$table_name}')
-							AND " . $this->db->sql_in_set('ix.name', array_keys($existing_indexes));
-				}
-				else
-				{
-					$sql = "SELECT DISTINCT ix.name AS phpbb_index_name, cols.name AS phpbb_column_name
-						FROM sys.indexes ix
-						INNER JOIN sys.index_columns ixc
-							ON ixc.object_id = ix.object_id
-								AND ixc.index_id = ix.index_id
-						INNER JOIN sys.columns cols
-							ON cols.column_id = ixc.column_id
-								AND cols.object_id = ix.object_id
-						WHERE ix.object_id = object_id('{$table_name}')
-							AND " . $this->db->sql_in_set('ix.name', array_keys($existing_indexes));
-				}
-			break;
-
 			case 'oracle':
 				$sql = "SELECT index_name AS phpbb_index_name, column_name AS phpbb_column_name
 					FROM all_ind_columns
@@ -2693,25 +2202,6 @@ class tools implements tools_interface
 	}
 
 	/**
-	* Is the used MS SQL Server a SQL Server 2000?
-	*
-	* @return bool
-	*/
-	protected function mssql_is_sql_server_2000()
-	{
-		if ($this->is_sql_server_2000 === null)
-		{
-			$sql = "SELECT CAST(SERVERPROPERTY('productversion') AS VARCHAR(25)) AS mssql_version";
-			$result = $this->db->sql_query($sql);
-			$properties = $this->db->sql_fetchrow($result);
-			$this->db->sql_freeresult($result);
-			$this->is_sql_server_2000 = $properties['mssql_version'][0] == '8';
-		}
-
-		return $this->is_sql_server_2000;
-	}
-
-	/**
 	* Returns the Queries which are required to recreate a table including indexes
 	*
 	* @param string $table_name