MySQL Bugs: #25957: Invalid Single Line Comment syntax recognized in \. command

Bug #25957	Invalid Single Line Comment syntax recognized in \. command
Submitted:	30 Jan 2007 23:47	Modified:	19 May 2009 17:26
Reporter:	John Foelster	Email Updates:
Status:	Won't fix	Impact on me:	None
Category:	MySQL Server: Command-line Clients	Severity:	S3 (Non-critical)
Version:	5.0, 5.1, 4.1	OS:	Windows (Windows XP Pro, Linux)
Assigned to:		CPU Architecture:	Any

Description:
Running saved batch scripts with the "\." Command will execute successfully if single line comments are included in the following format:

--This is not a comment

as opposed to the correct:

-- But this is

The Query Browser parser blocks the incorrect syntax correctly and this can cause some confusion if scripts are originally constructed for Command line interpretation are subsequently run via Query Browser.

How to repeat:
Running saved batch scripts with the "\." Command will execute successfully if single line comments are included in the following format:

--This is not a comment

as opposed to the correct:

-- But this is

Thank you for the report.

Verified as described on Linux using last BK sources. All versions are affected.

There is too much that relies on a leading '--' with no trailing space being treated as a comment by the mysql command-line client, so we won't change this default behavior. Using the --comments switch to mysql does cause all comments to be sent to the server, and it will barf on -- comments without a trailing space.

Might it then be permissible to consider that allowing the '--' comment syntax in query browser with a warning ought to be implemented?

I know consistency is the hobgoblin of small minds and all that, but still...

I've long since switched to Postgre for the project this bug report originated on for reasons of ease of db interactivity with a 3rd party db, so this is merely of academic interest, but still.

Better late than never, btw.

It's really a "duh" bug. I regularly meet developers who think that MySQL doesn't know single-line comments and use multi-line comments instead. It would really help to fix this nontheless.