MySQL Bugs: #38597: Table comments can be too long

Bug #38597	Table comments can be too long
Submitted:	6 Aug 2008 10:55	Modified:	7 Feb 2011 15:58
Reporter:	James Gordon	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Workbench	Severity:	S3 (Non-critical)
Version:	5.0.23	OS:	Windows (XP)
Assigned to:	Alexander Musienko	CPU Architecture:	Any

Description:
Multi-line table comments, when generated and ran causes an error.

How to repeat:
Create a simple table.
Create a multi-line comment ...

This table contains 1 row which is a 'Message of the Day'.
It can be empty.
Expiry Date is there to allow the expiration of a message.

Export->Forward Engineer.

When ran causes error...

ERROR 1105 (HY000) at line 97: Too long comment for table 'motd'

Thank you for the bug report. Could you please provide a project file test case?. Thanks in advance.

Original DBD file

Attachment: StdSchema.xml (text/xml), 137.58 KiB.

Import of DBD file.

Attachment: StdSchema.mwb (application/x-zip-compressed, text), 46.62 KiB.

have a look at the MOTD table for a long comment.

According to the manual (http://dev.mysql.com/doc/refman/5.0/en/create-table.html):

"- COMMENT

A comment for the table, up to 60 characters long."

In I_S.TABLES TABLE_COMMENT column is varchar(80);

If WB allows longer comments (as in your case) and does not truncate them, then it is a bug.

So in 5.0.29 this is still not fixed? This is really an inconvenient thing, because there is also no way to know how long table comment actually is (other than manually counting symbols).

Just tried with 5.0.30 and it still allows me to create very long comments.
It is the fact that the comments textbox is large and should really be a single line.

Validation already will recognise it.

The following changes will be made:

- no additional comment fields will be added
- the current comment field will be handled so that only the 1st line or the 1st 60 chars (whatever is shortest) will be forward engineered into DB
- during synchronization, only the begining of the comment will be compared. If it doesn't match, the DB comment will be added into the model
- using an empty line as the 1st line in the comment, will make the DB comment be empty
- the comment editor will highlight the DB comment in a different color to visualize the db comment boundary

Bug #47380 is a duplicate of this bug here.

Bug #51541 was marked as a duplicate of this one.

Bug #52244 has been marked as duplicate of this one

Having same issue. Has this been solved or is there a solution for this?

Bug #55238 has been marked as duplicate of this one

Bug #57070 has been marked as duplicate of this one

Bug #57110 has been marked as duplicate of this one

Bug #57594 has been marked as duplicate of this one

marked Bug #49847 as duplicate of this one

marked Bug #57901 as duplicate of this one

Bug #57970 was marked as a duplicate of this one.

Please, this is a very important bug, since it breaks the "Synchronyze" function.

2 years since first report and still there.

Can you just place an option to "Ignore Comments" as suggested. This will make it usable again.

I cannot believe that this has been going on for over 2 years with numerous duplicate bug being opened and closed and it still being ignored.
I would of thought that with so many dupliate bug it would be see as something that has annoyed a number of people and as it is so minor that fixing it would make a great deal of difference.

The solution to be implemented will be:

- truncate comments to be used for generated SQL in the 1st empty newline or at 60 bytes, whatever is shortest.

- when synchronizing, DB comments will be updated so that only the part up to the 1st empty newline is replaced with what comes from the server.

I'm also quite annoyed by this easy-to-fix bug, but found a little workaround today, hope it will help some of you until the bug is fixed.

I just removed the lines:
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL'; (3rd row)
SET SQL_MODE=@OLD_SQL_MODE; (3rd last row)
from the exported sql file, after that I didn't get an error for my long comments.

Please let me know if my change breaks anything else instead.

fix confirmed in repository, now the first 60 chars or text up to the first linebreak (whatever comes first) gets synced with database comments. (e.g. if you don't want to  have comments in DB just start with a linebreak)

An entry has been added to the 5.2.32 changelog:

Forward engineering a table containing a multi-line comment resulted in the following error:

ERROR 1105 (HY000) at line 97: Too long comment for table 'motd'

It is frustrating me. When I read Workbench 5.2.32. changelog I was excited. But now I see that it's still 60 character long comments. Yes, now it doesn't break synchronization but there is still problem with short length of comments. I really need more to describe database single table in database schema. 

Will this change in next releases?
Whether is this a problem in Workbench or MySQL server?