DevForce Community Forum : IIdGenerator using combined primary-keys

DevForce Community Forum : IIdGenerator using combined primary-keys http://www.ideablade.com/forum/ This is an XML content feed of; DevForce Community Forum : DevForce 2010 : IIdGenerator using combined primary-keys Wed, 29 Jul 2026 15:12:12 -700 Tue, 11 Jan 2011 01:08:35 -700 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 9.69 360 www.ideablade.com/forum/RSS_post_feed.asp?TID=2416 DevForce Community Forum http://www.ideablade.com/forum/forum_images/IdeaBlade_logo_tm.png http://www.ideablade.com/forum/ IIdGenerator using combined primary-keys : Hi Sbelini, Yes that was actualy... http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9618#9618 Author: tj62
Subject: 2416
Posted: 11-Jan-2011 at 1:08am

Hi Sbelini,

Yes that was actualy the work around I was going to take. Actualy I will do it in a trigger as follows (for those that might run into the same problem) I will let the trigger maintain the idA and idB for the old software (update and insert triggers). However I will change the primary/foreighn keys to serial (autoincrement) and maintain those from the silverlight system.

Such actually, I will have two key systems in the same table. Rather ugly but as the old application will disappear with the year(s) I can one day remove idA and idB. This also frees me from maintaing bad-keying system in the new Silverlight systems. It's quite a work re-keying all the foreighn tables (about 40 tables), but in the end I think it will pay off.

Regards

]]> Tue, 11 Jan 2011 01:08:35 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9618#9618 IIdGenerator using combined primary-keys : Hi tj62, Unfortunately, you... http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9614#9614 Author: sbelini
Subject: 2416
Posted: 10-Jan-2011 at 4:19pm

Hi tj62,

Unfortunately, you won't be able to reference an entity (or its ID for that matter) in the IIdGenerator. You could still use it to generate your ids, but not if the ids to be generated are dependent on another row value as criteria.

What I can suggest is to implement this logic in an stored procedure. There you can access the FK (idA), check for the max value of the partial primary key (idB) for the rows matching idA, and then assign the value of idB properly.

Best regards,

Silvio.

]]> Mon, 10 Jan 2011 16:19:53 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9614#9614 IIdGenerator using combined primary-keys : Any idea before I start working... http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9558#9558 Author: tj62
Subject: 2416
Posted: 05-Jan-2011 at 1:23am

Any idea before I start working on a horrible workaround?]]> Wed, 05 Jan 2011 01:23:05 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9558#9558 IIdGenerator using combined primary-keys : I recently started implementing... http://www.ideablade.com/forum/forum_posts.asp?TID=2416&PID=9548#9548 Author: tj62
Subject: 2416
Posted: 04-Jan-2011 at 4:31am

I recently started implementing the IIdGenerator interface as I need pritty advanced id-generation. There are some rules I'm forced to follow when creating this, as the database is shared with some old software systems written in C++ and more. Unfortunately I'm not allowed to change the database using GUID or autoincrements. Let me simplify things by explaining a general example. Let us say we have two tabels defined such:

tableA

int idA // primary key

varchar(50) aName

tableB

int idA // partial primary key and foreighn key to tableA

int idB // partial primary key

varchar(50) bName

As you se, the primary key of tableB is made up by two integers where the first one is a foreighn key to tableA.

The rules are such whenever I create an entry in tableB, idB has to increment from one (1). Example

TableA

idA = 1

   TableB
       idA = 1
       idB = 1 (for the first record under TableA.idA=1)

idB = 2 (for the second record under TableA.idA=1)

idB = 3 (for the third record under TableA.idA=1)

TableA

idA = 2

   TableB
       idA = 2
       idB = 1 (for the first record under TableA.idA=2)

idB = 2 (for the second record under TableA.idA=2)

So I allways have to stard idB from 1 in TableB, for each new record in TableA

The problem is how can I in the server side call to

public UniqueIdMap GetRealIdMap(UniqueIdCollection tempIds, IDataSourceKey dataSourceKey)

find out for what idA it is called when requesting real Id for for TableB.idB? If I had that information it would be easy for my to request a valid idB from the database in GetRealIdMap. But without it I can't.

Second question is If I add entities to TableA as well as TableB and then perform save (both eintities with temporary Ids) is it guranteed that the TableA entity is saved first before calling GetRealIdMap for the TableB entity so that I know the real idA at that time...or is it all done in one call to GetRealIdMap?

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