SQLyog GUI provides an option to highlight any set of statements in the Editor and 'comment-out' those statements. And to revert back again (un-commenting) too, of course.
The purpose of this is to provide a fast way to 'exclude' one or more statements in an Editor tab from execution with 'execute all'. It simply does so by replacing
this_statement;
with
-- this_statement;
The 'remove comments' functionality only removes this type of comments and only when they start on the first position of the line
This means that all comments like
1)
# comment
2)
some_statement; -- comment here not starting at first position
3)
/* comment */
4)
/* multi-
line
comment */
are not touched. And it never was the intention to do!
If you use SQLyog as your only or primary GUI-client you can reserve the
-- style comments
for use with the SQLyog add/remove comments functionality and use the other available comment-styles for comments that should be permanent in the code.