diff --git a/framework/yii/db/mssql/QueryBuilder.php b/framework/yii/db/mssql/QueryBuilder.php
index 338a74b..77b9532 100644
--- a/framework/yii/db/mssql/QueryBuilder.php
+++ b/framework/yii/db/mssql/QueryBuilder.php
@@ -60,6 +60,47 @@ class QueryBuilder extends \yii\db\QueryBuilder
 //	}
 
 	/**
+	 * Builds a SQL statement for renaming a DB table.
+	 * @param string $table the table to be renamed. The name will be properly quoted by the method.
+	 * @param string $newName the new table name. The name will be properly quoted by the method.
+	 * @return string the SQL statement for renaming a DB table.
+	 */
+	public function renameTable($table, $newName)
+	{
+		return "sp_rename '$table', '$newName'";
+	}
+
+	/**
+	 * Builds a SQL statement for renaming a column.
+	 * @param string $table the table whose column is to be renamed. The name will be properly quoted by the method.
+	 * @param string $name the old name of the column. The name will be properly quoted by the method.
+	 * @param string $newName the new name of the column. The name will be properly quoted by the method.
+	 * @return string the SQL statement for renaming a DB column.
+	 */
+	public function renameColumn($table, $name, $newName)
+	{
+		return "sp_rename '$table.$name', '$newName', 'COLUMN'";
+	}
+
+	/**
+	 * Builds a SQL statement for changing the definition of a column.
+	 * @param string $table the table whose column is to be changed. The table name will be properly quoted by the method.
+	 * @param string $column the name of the column to be changed. The name will be properly quoted by the method.
+	 * @param string $type the new column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
+	 * into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
+	 * For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
+	 * @return string the SQL statement for changing the definition of a column.
+	 */
+	public function alterColumn($table, $column, $type)
+	{
+		$type=$this->getColumnType($type);
+		$sql='ALTER TABLE ' . $this->db->quoteTableName($table) . ' ALTER COLUMN '
+			. $this->db->quoteColumnName($column) . ' '
+			. $this->getColumnType($type);
+		return $sql;
+	}
+
+	/**
 	 * Builds a SQL statement for enabling or disabling integrity check.
 	 * @param boolean $check whether to turn on or off the integrity check.
 	 * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.