I've been using and doing upgrades from Drupal 5.1 through 5.10 for a site with no real issues.
Each time I would copy my database to a new one and point the settings.php to the new db, so as to leave the original in tact.
I'm using MySQL 4.1.22.
I thought I'd try a new install of 6.4 last night and try it out. Install went fine.
Then of course less than 12 hours later, 6.5 is out.
Well no biggy. I haven't installed any modules or anything special.
But upon trying to do my normal db copy, everything goes fine until I hit the 'users' table, where I get this error:
INSERT INTO `Drupal6_5`.`users`
SELECT *
FROM `Drupal6_4`.`users`
MySQL said:
#1062 - Duplicate entry '1' for key 1
At that point it never got to the remaining tables, so I don't know if it's the only table with the issue.
I can see what's happening, and why it wasn't doing it on my 5.x db's.
Looking at both the 6.4 and 6.5 'user' tables, both have the 'uid' set as "auto increment".
This is a clean 6.4 install, and in addition to the user '1' admin account, I made one other user account, which it added with no problem.
Looking at the contents of the 6.4 users table, I see the following entries:
(uid, name)
0, (blank)
1, AdminUser
3, OtherUser
I don't know if the uid 0 was there as soon as I finished the new install or after I added a second user.