what is the use of @@,@,#.## key words in sql server?

I am sorry Prasad, I am unaware of the # and ## in SQL server. Never came across this, can you give me an example where you have used this before?

Thanks 

Hi Prasad,

What I think is they are not the reserved keywords in the SQL Server. You can get the list of reserved keywords at:- https://msdn.microsoft.com/en-us/library/ms189822.aspx 

These are the syntactical expressions which differentiate normal letters from the SQL understandable keywords. Now for example,

@@ROWCOUNT, if we write only ROWCOUNT we would get syntax error. Saying Invalid syntax near ROWCOUNT. Thus append @@ and it understands. Similarly are the other expressions you have mentioned.

I hope this helps you some way.

Accept if helps.

Thanks