mysql comment symbols
9.6 Comment Syntax
From a “#” character to the end of the line.
From a “-- ” sequence to the end of the line. In MySQL,
the “-- ” (double-dash) comment style requires the second dash to be followed
by at least one whitespace or control character (such as a space, tab, newline, and so on).
This syntax differs slightly from standard SQL comment syntax, ...
From a /* sequence to the following */ sequence, as in the C programming language. ...
The following example demonstrates all three comment styles:
mysql> SELECT 1+1; # This comment continues to the end of line
mysql> SELECT 1+1; -- This comment continues to the end of line
mysql> SELECT 1 /* this is an in-line comment */ + 1;
mysql> SELECT 1+
this is a