Hi.
On Thu, Jul 19, 2001 at 07:24:17PM +0100, [EMAIL PROTECTED] wrote:
>
> I have been searching through the manual and the list archives for the last
> few days regarding a problem I have with the SET column type.
>
[...]
> For example
>
> UPDATE users SET user_flags = CONCAT(user_flags,'pass_renew') WHERE user_id = 1
As Don has said, there is only a comma missing. But this will issue a
warning if user_flags is empty (because there is a spare comma. The
following is a variant which doesn't show a warning, but is a bit
more complex:
UPDATE users
SET user_flags = CONCAT(type, IF(type=0,"",","), "pass_renew")
WHERE user_id = 1
The equivalent for removing a flag (without warning) is:
UPDATE users
SET user_flags = user_flags & ~(1 << FIND_IN_SET("pass_renew",user_flags)-1)
WHERE user_id = 1
The simplier variant (with warning), would be
UPDATE users
SET user_flags = REPLACE(user_flags, 'pass_renew', '')
WHERE user_id = 1
Note that this requires that there is no further flag which contains
'pass_renew' as a substring.
> Any help or pointers would be greatly appreciated.
>
> Thanks
>
> Nick Brandon
> P.S. Please cc my email address as I'm not subscribe to the list - Thanks
Btw, the above has been the result of a discussion on the list between
Ed Heron and me in November 1999, which can be read in the MySQL
mailing list archive:
http://lists.mysql.com/cgi-ez/ezmlm-cgi?1:msn:19582:bpheegjloglblgfaoplk
(btw, the thread is the second match when searching for "update concat set" ;-)
Bye,
Benjamin.
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