Hi, I have a situation where I am parsing an XML file, and in the process I create several related groups of objects. I am currently creating and saving each one in sequence, but this is causing a huge number of COMMIT's to be called in the SQL. What I would like to do, is store every object of the same type that is created in an array, and then save them all at once, wrapped in a transaction call, so that there is only one COMMIT called on every table. The problem I'm having is that there is an order of dependency among the objects, so Object2 depends on Object1's id as its foreign key. Without the call to save, Object1 does not have an id assigned to it, so the eventual save on object 2 fails. Is there any way to get this value (auto-incrementing in the DB) without all the extra overhead? Thanks, Simon
on 2007-03-30 17:04
on 2007-03-30 17:20
On 30 Mar 2007, at 16:03, Simon wrote: > fails. Is there any way to get this value (auto-incrementing in the > DB) without all the extra overhead? An object doesn't have to be saved for you to relate other objects to it. Note that the point when objects are saved depends on which way round you associate them. So if you assign an object to a has_one relationship in an existing object, that associated object will be automatically saved. But if you assign a new object to a belongs_to relationship, it won't be automatically saved. See pp 356-357 of Agile Web Development With Rails v2. Hope that helps. Regards, Andy Stewart
on 2007-03-31 18:07
How would you write SQL to do that? The only way I can think you would do it is to use a stored procedure, generate your own primary keys (hoping they don't clash!!!), and do something like an IDENTITY_INSERT. Otherwise you will have to insert the row to get its primary key. If all you need is a single transaction, then maybe you can use Object.transaction. But I thought I heard a rumour that that was being depreciated. Is that true?