SQL Server Date format operation

Date to string-date
Select CONVERT (varchar (+), GETDATE (), max) from Regionrealtimedata

Date to string-full
Select CONVERT (varchar), GETDATE (), () from Regionrealtimedata

(To_char (To_date (fdate, ' yyyy-mm-dd '), ' yyyy-mm-dd '))
String Goto Date-Date
Select CONVERT (varchar), cast (' 2015-1-1 ' as datetime), Max. From Regionrealtimedata

String Goto Date-Full
Select cast (' 2015-1-1 ' as datetime) from Regionrealtimedata

Filter conditions-month
DATEPART (Month,cast (a.fdate as datetime)) =11

SQL Server Date format operation