You can use convert function for example
SELECT LEFT(CONVERT(VARCHAR(100),GETDATE(),109),11)Or, more simply
SELECT CONVERT(VARCHAR(11),GETDATE(),109). The result depends on the language setting on the computer. If you are on SQL 2012, you can use the FORMAT function, which is more flexible - http://msdn.microsoft.com/en-us/library/hh213505.aspx
Unless there is a compelling reason to do the formatting in SQL, usually it is better to do the formatting and conversions at the client side or other end-point where the data is consumed.