ID Generating !

hesam · **Joined:** Mon Aug 22, 2005 3:13 am **Posts:** 3

Hi.

first of all i wanna thank all you guys .
Hibernate is perfect. :)

my problem :( :
i am new to hibernate and wanna implement a
"20-bit" ID Generator.
I am using MySQL as a Database.

i dont know how :(
is there any common algorithm ?
is there any generator ?

it seems too dificult to me.

i ll be thankful if u help me.

[/i]

hesam · **Joined:** Mon Aug 22, 2005 3:13 am **Posts:** 3

hesam wrote:

Hi.

first of all i wanna thank all you guys .
Hibernate is perfect. :)

my problem :( :
i am new to hibernate and wanna implement a
"20-bit" ID Generator.
I am using MySQL as a Database.

i dont know how :(
is there any common algorithm ?
is there any generator ?

it seems too dificult to me.

i ll be thankful if u help me.

[/i]

What's a problem if i substring GUID to generate 20 char ID ?

jamie_dainton · **Posted:** Mon Aug 22, 2005 5:00 am

If you need really need a custom ID generator then implement IdentifierGenerator and write your own generator.

See the files in org.hibernate.id for more information.

Paul Newport · **Posted:** Mon Aug 22, 2005 11:00 am

my problem :( :
i am new to hibernate and wanna implement a
"20-bit" ID Generator.
I am using MySQL as a Database.

[/i][/quote]

Why don't you let mySQL generate it using an identity column ?

hesam · **Joined:** Mon Aug 22, 2005 3:13 am **Posts:** 3

Paul Newport wrote:

my problem :( :
i am new to hibernate and wanna implement a
"20-bit" ID Generator.
I am using MySQL as a Database.

[/i]

Why don't you let mySQL generate it using an identity column ?[/quote]

would you tell more about identity column .
can i have unique ID with lenght of 20 with that?
its length is very important to me .

and about GUID i found out that it's sortable and i think substring of that
cant make a Duplicate Key trouble.

by the way i have not large amount of data max, 1,000,000

thanks

jamie_dainton · **Posted:** Mon Aug 22, 2005 12:22 pm

Link to the page in the MySQL documentation that explains it.

http://dev.mysql.com/doc/maxdb/en/6d/11 ... ameset.htm

Paul Newport · **Posted:** Mon Aug 22, 2005 3:04 pm

Can you explain why you want to manage the surrogate key yourself ?

Surrogate keys should be inheritently meaningless, and if the database can generate them all the better, as you don't need to worry about it.

If the database supports surrogate key generation natively as in an identity column, why not let the database handle it and get on with the important stuff, the application code ?