diff --git a/yii/db/mssql/PDO.php b/yii/db/mssql/PDO.php
new file mode 100644
index 0000000..e045d68
--- /dev/null
+++ b/yii/db/mssql/PDO.php
@@ -0,0 +1,68 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db\mssql;
+
+/**
+ * This is an extension of default PDO class for MSSQL and DBLIB drivers. It provides workaround for improperly
+ * implemented functionalities of the drivers.
+ *
+ * @author Timur Ruziev <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class PDO extends \PDO
+{
+	/**
+	 * Returns last inserted ID value.
+	 *
+	 * @param string|null sequence the sequence name. Defaults to null.
+	 * @return integer last inserted ID value.
+	 */
+	public function lastInsertId($sequence = null)
+	{
+		return $this->query('SELECT CAST(COALESCE(SCOPE_IDENTITY(), @@IDENTITY) AS bigint)')->fetchColumn();
+	}
+
+	/**
+	 * Begin a transaction.
+	 *
+	 * Is is necessary to override PDO's method as MSSQL PDO drivers does not support transactions.
+	 *
+	 * @return boolean
+	 */
+	public function beginTransaction()
+	{
+		$this->exec('BEGIN TRANSACTION');
+		return true;
+	}
+
+	/**
+	 * Commit a transaction.
+	 *
+	 * Is is necessary to override PDO's method as MSSQL PDO drivers does not support transactions.
+	 *
+	 * @return boolean
+	 */
+	public function commit()
+	{
+		$this->exec('COMMIT TRANSACTION');
+		return true;
+	}
+
+	/**
+	 * Rollback a transaction.
+	 *
+	 * Is is necessary to override PDO's method as MSSQL PDO drivers does not support transaction.
+	 *
+	 * @return boolean
+	 */
+	public function rollBack()
+	{
+		$this->exec('ROLLBACK TRANSACTION');
+		return true;
+	}
+}
diff --git a/yii/db/mssql/QueryBuilder.php b/yii/db/mssql/QueryBuilder.php
new file mode 100644
index 0000000..f4f2088
--- /dev/null
+++ b/yii/db/mssql/QueryBuilder.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db\mssql;
+
+/**
+ * QueryBuilder is the query builder for MS SQL database (version 2008 and above).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Christophe Boulain <Christophe.Boulain@gmail.com>
+ * @author Timur Ruziev <resurtm@gmail.com>
+ * @since 2.0
+ */
+class QueryBuilder extends \yii\db\QueryBuilder
+{
+	/**
+	 * @var array mapping from abstract column types (keys) to physical column types (values).
+	 */
+	public $typeMap = array(
+		Schema::TYPE_PK => 'int IDENTITY PRIMARY KEY',
+		Schema::TYPE_STRING => 'varchar(255)',
+		Schema::TYPE_TEXT => 'text',
+		Schema::TYPE_SMALLINT => 'smallint(6)',
+		Schema::TYPE_INTEGER => 'int(11)',
+		Schema::TYPE_BIGINT => 'bigint(20)',
+		Schema::TYPE_FLOAT => 'float',
+		Schema::TYPE_DECIMAL => 'decimal',
+		Schema::TYPE_DATETIME => 'datetime',
+		Schema::TYPE_TIMESTAMP => 'timestamp',
+		Schema::TYPE_TIME => 'time',
+		Schema::TYPE_DATE => 'date',
+		Schema::TYPE_BINARY => 'binary',
+		Schema::TYPE_BOOLEAN => 'tinyint(1)',
+		Schema::TYPE_MONEY => 'decimal(19,4)',
+	);
+}
diff --git a/yii/db/mssql/Schema.php b/yii/db/mssql/Schema.php
new file mode 100644
index 0000000..72171bd
--- /dev/null
+++ b/yii/db/mssql/Schema.php
@@ -0,0 +1,292 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db\mssql;
+
+use yii\db\TableSchema;
+use yii\db\ColumnSchema;
+use yii\helpers\ArrayHelper;
+
+/**
+ * Schema is the class for retrieving metadata from a MS SQL database (version 2008 and above).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Christophe Boulain <Christophe.Boulain@gmail.com>
+ * @author Timur Ruziev <resurtm@gmail.com>
+ * @since 2.0
+ */
+class Schema extends \yii\db\Schema
+{
+	/**
+	 * Default schema name to be used.
+	 */
+	const DEFAULT_SCHEMA = 'dbo';
+
+	/**
+	 * @var array mapping from physical column types (keys) to abstract column types (values)
+	 */
+	public $typeMap = array(
+		// TODO: mssql driver
+	);
+
+	/**
+	 * Quotes a table name for use in a query.
+	 * A simple table name has no schema prefix.
+	 * @param string $name table name.
+	 * @return string the properly quoted table name.
+	 */
+	public function quoteSimpleTableName($name)
+	{
+		return strpos($name, '[') !== false ? $name : '[' . $name . ']';
+	}
+
+	/**
+	 * Quotes a column name for use in a query.
+	 * A simple column name has no prefix.
+	 * @param string $name column name.
+	 * @return string the properly quoted column name.
+	 */
+	public function quoteSimpleColumnName($name)
+	{
+		return strpos($name, '[') !== false || $name === '*' ? $name : '[' . $name . ']';
+	}
+
+	/**
+	 * Creates a query builder for the MSSQL database.
+	 * @return QueryBuilder query builder interface.
+	 */
+	public function createQueryBuilder()
+	{
+		return new QueryBuilder($this->db);
+	}
+
+	/**
+	 * Loads the metadata for the specified table.
+	 * @param string $name table name
+	 * @return TableSchema driver dependent table metadata. Null if the table does not exist.
+	 */
+	public function loadTableSchema($name)
+	{
+		$table = new TableSchema();
+		$this->resolveTableNames($table, $name);
+		$this->findPrimaryKeys($table);
+
+		if ($this->findColumns($table)) {
+			$this->findConstraints($table);
+			return $table;
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Collects the metadata of table columns.
+	 * @param TableSchema $table the table metadata
+	 * @return boolean whether the table exists in the database
+	 */
+	protected function findColumns($table)
+	{
+		$columnsTableName = 'INFORMATION_SCHEMA.COLUMNS';
+		$whereSql = "t1.TABLE_NAME = '" . $table->name . "'";
+		if ($table->catalogName !== null) {
+			$columnsTableName = $table->catalogName . '.' . $columnsTableName;
+			$whereSql .= " AND t1.TABLE_CATALOG = '" . $table->catalogName . "'";
+		}
+		if ($table->schemaName !== null) {
+			$whereSql .= " AND t1.TABLE_SCHEMA = '" . $table->schemaName . "'";
+		}
+		$columnsTableName = $this->quoteTableName($columnsTableName);
+
+		$sql = <<<SQL
+SELECT
+	t1.*,
+	columnproperty(object_id(t1.table_schema + '.' + t1.table_name), t1.column_name, 'IsIdentity') AS IsIdentity,
+	CONVERT(VARCHAR, t2.value) AS Comment
+FROM {$columnsTableName} AS t1
+LEFT OUTER JOIN sys.extended_properties AS t2 ON
+	t1.ORDINAL_POSITION = t2.minor_id AND
+	object_name(t2.major_id) = t1.TABLE_NAME AND
+	t2.class = 1 AND
+	t2.class_desc = 'OBJECT_OR_COLUMN' AND
+	t2.name = 'MS_Description'
+WHERE {$whereSql}
+SQL;
+
+		try {
+			$columns = $this->db->createCommand($sql)->queryAll();
+		} catch (\Exception $e) {
+			return false;
+		}
+		foreach ($columns as $column) {
+			$column = $this->loadColumnSchema($column);
+			if (is_array($table->primaryKey)) {
+				$column->isPrimaryKey = count(preg_grep('/' . preg_quote($column->name) . '/i', $table->primaryKey)) > 0;
+			} else {
+				$column->isPrimaryKey = strcasecmp($column->name, $table->primaryKey) === 0;
+			}
+			$table->columns[$column->name] = $column;
+			if ($column->isPrimaryKey && $column->autoIncrement) {
+				$table->sequenceName = '';
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Collects the primary key column details for the given table.
+	 * @param TableSchema $table the table metadata
+	 */
+	protected function findPrimaryKeys($table)
+	{
+		$keyColumnUsageTableName = 'INFORMATION_SCHEMA.KEY_COLUMN_USAGE';
+		$tableConstraintsTableName = 'INFORMATION_SCHEMA.TABLE_CONSTRAINTS';
+		if ($table->catalogName !== null) {
+			$keyColumnUsageTableName = $table->catalogName . '.' . $keyColumnUsageTableName;
+			$tableConstraintsTableName = $table->catalogName . '.' . $tableConstraintsTableName;
+		}
+		$keyColumnUsageTableName = $this->quoteTableName($keyColumnUsageTableName);
+		$tableConstraintsTableName = $this->quoteTableName($tableConstraintsTableName);
+
+		$sql = <<<SQL
+SELECT
+	kcu.column_name AS field_name
+FROM {$keyColumnUsageTableName} AS kcu
+LEFT JOIN {$tableConstraintsTableName} AS tc ON
+	kcu.table_name = tc.table_name AND
+	kcu.constraint_name = tc.constraint_name
+WHERE
+	tc.constraint_type = 'PRIMARY KEY' AND
+	kcu.table_name = :tableName AND
+	kcu.table_schema = :schemaName
+SQL;
+
+		$table->primaryKey = $this->db
+			->createCommand($sql, array(':tableName' => $table->name, ':schemaName' => $table->schemaName))
+			->queryColumn();
+		if (count($table->primaryKey) == 0) {
+			// table does not have primary key
+			$table->primaryKey = null;
+		} elseif (count($table->primaryKey) == 1) {
+			// table have one primary key
+			$table->primaryKey = $table->primaryKey[0];
+		}
+	}
+
+	/**
+	 * Loads the column information into a [[ColumnSchema]] object.
+	 * @param array $info column information
+	 * @return ColumnSchema the column schema object
+	 */
+	protected function loadColumnSchema($info)
+	{
+		$column = new ColumnSchema();
+		$column->name = $info['COLUMN_NAME'];
+		$column->comment = $info['Comment'] === null ? '' : $column['Comment'];
+
+		$column->dbType = $info['DATA_TYPE'];
+		$column->unsigned = stripos($column->dbType, 'unsigned') !== false;
+		$column->allowNull = $info['IS_NULLABLE'] == 'YES';
+
+		$column->isPrimaryKey = null; // primary key is determined in findColumns() method
+		$column->autoIncrement = $info['IsIdentity'] == 1;
+
+		$column->type = self::TYPE_STRING;
+		// TODO: better type infer
+
+		$column->phpType = $this->getColumnPhpType($column);
+		return $column;
+	}
+
+	/**
+	 * Collects the foreign key column details for the given table.
+	 * @param TableSchema $table the table metadata
+	 */
+	protected function findConstraints($table)
+	{
+		$referentialConstraintsTableName = 'INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS';
+		$keyColumnUsageTableName = 'INFORMATION_SCHEMA.KEY_COLUMN_USAGE';
+		if ($table->catalogName !== null) {
+			$referentialConstraintsTableName = $table->catalogName . '.' . $referentialConstraintsTableName;
+			$keyColumnUsageTableName = $table->catalogName . '.' . $keyColumnUsageTableName;
+		}
+		$referentialConstraintsTableName = $this->quoteTableName($referentialConstraintsTableName);
+		$keyColumnUsageTableName = $this->quoteTableName($keyColumnUsageTableName);
+
+		// please refer to the following page for more details:
+		// http://msdn2.microsoft.com/en-us/library/aa175805(SQL.80).aspx
+		$sql = <<<SQL
+SELECT
+	kcu1.COLUMN_NAME AS fk_column_name,
+	kcu2.TABLE_NAME AS uq_table_name,
+	kcu2.COLUMN_NAME AS uq_column_name
+FROM {$referentialConstraintsTableName} AS rc
+JOIN {$keyColumnUsageTableName} AS kcu1 ON
+	kcu1.CONSTRAINT_CATALOG = rc.CONSTRAINT_CATALOG AND
+	kcu1.CONSTRAINT_SCHEMA = rc.CONSTRAINT_SCHEMA AND
+	kcu1.CONSTRAINT_NAME = rc.CONSTRAINT_NAME
+JOIN {$keyColumnUsageTableName} AS kcu2 ON
+	kcu2.CONSTRAINT_CATALOG = rc.UNIQUE_CONSTRAINT_CATALOG AND
+	kcu2.CONSTRAINT_SCHEMA = rc.UNIQUE_CONSTRAINT_SCHEMA AND
+	kcu2.CONSTRAINT_NAME = rc.UNIQUE_CONSTRAINT_NAME AND
+	kcu2.ORDINAL_POSITION = kcu1.ORDINAL_POSITION
+WHERE kcu1.TABLE_NAME = :tableName
+SQL;
+
+		$rows = $this->db->createCommand($sql, array(':tableName' => $table->name))->queryAll();
+		$table->foreignKeys = array();
+		foreach ($rows as $row) {
+			$table->foreignKeys[] = array($row['uq_table_name'], $row['fk_column_name'] => $row['uq_column_name']);
+		}
+	}
+
+	/**
+	 * Resolves the table name and schema name (if any).
+	 * @param TableSchema $table the table metadata object
+	 * @param string $name the table name
+	 */
+	protected function resolveTableNames($table, $name)
+	{
+		$parts = explode('.', str_replace(array('[', ']'), '', $name));
+		$partCount = count($parts);
+		if ($partCount == 3) {
+			// catalog name, schema name and table name provided
+			$table->catalogName = $parts[0];
+			$table->schemaName = $parts[1];
+			$table->name = $parts[2];
+		} elseif ($partCount == 2) {
+			// only schema name and table name provided
+			$table->schemaName = $parts[0];
+			$table->name = $parts[1];
+		} else {
+			// only schema name provided
+			$table->schemaName = static::DEFAULT_SCHEMA;
+			$table->name = $parts[0];
+		}
+	}
+
+	/**
+	 * Returns all table names in the database.
+	 * This method should be overridden by child classes in order to support this feature
+	 * because the default implementation simply throws an exception.
+	 * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
+	 * @return array all table names in the database. The names have NO the schema name prefix.
+	 */
+	protected function findTableNames($schema = '')
+	{
+		if ('' === $schema) {
+			$schema = self::DEFAULT_SCHEMA;
+		}
+		$sql = "SELECT TABLE_NAME FROM [INFORMATION_SCHEMA].[TABLES] WHERE TABLE_SCHEMA = :schema AND TABLE_TYPE = 'BASE TABLE'";
+		$names = $this->db->createCommand($sql, array(':schema' => $schema))->queryColumn();
+		if (self::DEFAULT_SCHEMA !== $schema) {
+			foreach ($names as $index => $name) {
+				$names[$index] = $schema . '.' . $name;
+			}
+		}
+		return $names;
+	}
+}
diff --git a/yii/db/mssql/SqlsrvPDO.php b/yii/db/mssql/SqlsrvPDO.php
new file mode 100644
index 0000000..607d0e4
--- /dev/null
+++ b/yii/db/mssql/SqlsrvPDO.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db\mssql;
+
+/**
+ * This is an extension of default PDO class for MSSQL SQLSRV driver. It provides workaround for improperly
+ * implemented functionalities of the PDO SQLSRV driver.
+ *
+ * @author Timur Ruziev <resurtm@gmail.com>
+ * @since 2.0
+ */
+class SqlsrvPDO extends \PDO
+{
+	/**
+	 * Returns last inserted ID value.
+	 *
+	 * SQLSRV driver supports PDO::lastInsertId() with one peculiarity: when $sequence value is null
+	 * or empty string it returns empty string. But when parameter is not specified it's working
+	 * as expected and returns actual last inserted ID (like the other PDO drivers).
+	 *
+	 * @param string|null $sequence the sequence name. Defaults to null.
+	 * @return integer last inserted ID value.
+	 */
+	public function lastInsertId($sequence = null)
+	{
+		return !$sequence ? parent::lastInsertId() : parent::lastInsertId($sequence);
+	}
+}