Two hyphens (--) are put just before the text to be commented. This type of comment extends only up to the end of the commented line.
CREATE TABLE Students
-- A table named Students
(
Id INT PRIMARY KEY, -- with Primary Key as Id
Name VARCHAR (50) NOT NULL,
Address VARCHAR (40) NOT NULL,
Phone INT
) --- will be created-----
Creates the Students table. The text after -- in each line are comments and will not be evaluated by the SQL Server.