Hi,

I have a table lets say
TblHD
{
id : int auto_increment primary_key;
codeno : varchar(12) ; // unique ;
... other fields ....
}

id is autoincrement and i used it for creating primary key.
codeno is like id, but it is for user to identify the transaction
number (it is sequence in number format)

my question is, if i have id, should i have codeno or i just need
id ?
what if in the transaction happens like this ...

user1 : entry a transaction at the same time with user2 and user1 get
first id (lets say '1') and user2 get id (lets say '2'). But in the
middle, trigger for user 1 was raised an exception and the
transacation was canceled. is the user2 get id 2 or he got 1 ?

is mysql auto increment behave the same thing like in oracle
sequences ?
can autoincrement rolledback ? afaik in oracle the sequences wont
rolled back. how about in mysql.

tx

Adwin Wijaya:

> is mysql auto increment behave the same thing like in oracle
> sequences ?
> can autoincrement rolledback ?

No. Once your application issued an INSERT query, it may get the
autoincremented primary key returned and anticipate on that.

A rollback of the autoincremented value would have disastrous
consequences for the remainder of the functionality.

--
Erick