There are three types of comment:
# This comment continues to the end of line -- This comment continues to the end of line /* This is an in-line comment */ /* This is a multiple-line comment */
SELECT * FROM t1; -- this is comment CREATE TABLE stack( /*id_user int, username varchar(30), password varchar(30) */ id int );
-- method requires that a space follows the
-- before the comment begins, otherwise it will be interpreted as a command and usually cause an error.
#This comment works /*This comment works.*/ --This comment does not.