Hi
You are not defining num so you are adding 1 to 0 to get 1 and you
already have that record. Sounds like you need an autoincrement field.
Mike
----- Original Message -----
From: "Mark Rages" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: June 5, 2003 7:52 PM
Subject: I thought single UPDATE statements were atomic
> According to the docs, single update statements are atomic.
>
> So why doesn't this work?
>
> mysql> create table t (num INT, UNIQUE (num));
> Query OK, 0 rows affected (0.00 sec)
>
> mysql> insert into t values ('1');
> Query OK, 1 row affected (0.00 sec)
>
> mysql> insert into t values ('2');
> Query OK, 1 row affected (0.00 sec)
>
> mysql> select * from t;
> +------+
> | num |
> +------+
> | 1 |
> | 2 |
> +------+
> 2 rows in set (0.00 sec)
>
> mysql> update t set num=num+1;
> ERROR 1062: Duplicate entry '2' for key 1
> mysql>
>
> Help!
>
> Regards,
> Mark
> [EMAIL PROTECTED]
>
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