Single-line and multiline comments for SQL Server

Environment: SQL Server 2008 R2

Question: The annotation usage in SQL Server is not clear.

Solve:

Single-line Comment:--

Multi-line Comment:/*......*/

Use examples:

Single-line Comment:

-The column ' Student.sname ' in the select list is 

not valid because the column is not included in an aggregate function or a GROUP by clause.  
SELECT Student.sno,sname,avg (grade) as Avg_g  
From  student,sc  
WHERE student.sno=sc.sno and cno<> ' 008 '
GROUP by Student.sno-no  Student. Column name ' Sno ' not clear.  
having  MIN (grade) >= by  avg_g  DESC;

Multi-line Comment:

/*  
grant all permissions to the Student table and Course table to users U2 and U3   
 grant all priviliges on   
               table Student, Course to   
                      U2, U3;    
Grant the query permissions on the table SC to all users   
grant SELECT on table SC to public   
;  
Grant the user U4 GRANT UPDATE (Sno) the Query Student table and the permission to modify the student number   
, SELECT on
                      table Student to U4;   
 REVOKE UPDATE (Sno) on the TABLE Student from U4 the user U4 modify the student number's permission;  
*/