Problem saving entities containing collections

mindonwarp · **Joined:** Fri Sep 23, 2011 4:47 am **Posts:** 2

Hi guys, I need some help.

I'm just starting out with NHibernate and I'm using Fluent for mappings. Everything seemed to work fine until today.
Here is the story:

I have two tables in my db: Store and WorkDay
The first table contains info about the store, and the WorkDay table contains info about the days of week and start/end time when the store is open.
Store contains a Guid StoreID PK column that is referenced in the WorkDay table.
So I have a mapping file for Store where I have a HasMany association with the WorkDay table, and a corresponding POCO for Store.
Now, when I fill in all the necessary data and try to persist it to database, I get an exception telling me that the insert into table WorkDay failed because the StoreID had null value and the table constraint doesn't allow nulls for that column (which is, of course, expected behavior).

I understand the reason for this exception, but I don't know how to solve it.
The reason why the insert fails is because the StoreID gets generated upon insert, but the WorkDay collection gets saved first, in the time when the StoreID hasn't yet been generated!

So, how do I force NHibernate to generate this ID to pass it to dependent tables? Or is there another solution for this?

Thank you!

meetmrharish · **Joined:** Fri Nov 19, 2010 4:02 am **Posts:** 11

Hi,

You need to fill the the parent entity reference in child entity also (i.e variable referring the parent in child class) so that it takes the reference of parent entity primary key to set the FK column of the child

Cheers,
Harish

mindonwarp · **Joined:** Fri Sep 23, 2011 4:47 am **Posts:** 2

Hi Harish, thanks for your reply!

Shouldn't this be done automatically?
This is what I have in my StoreMap:

Code:

HasMany(x => x.WorkDays)
      .Inverse().KeyColumn("StoreID").ForeignKeyCascadeOnDelete()
      .Cascade.All();

and this is what's in the WorkDayMap

Code:

References(x => x.Store).Column("StoreID");

emmahudson88 · **Joined:** Sun Sep 25, 2011 10:06 pm **Posts:** 1

mindonwarp wrote:

Hi guys, I need some help.

I'm just starting out with NHibernate and I'm using Fluent for mappings. Everything seemed to work fine until today.
Here is the story:

I have two tables in my db: Store and WorkDay
The first table contains info about the store, and the WorkDay table contains info about the days of week and start/end time when the store is open.
Store contains a Guid StoreID PK column that is referenced in the WorkDay table.
So I have a mapping file for Store where I have a HasMany association with the WorkDay table, and a corresponding POCO for Store.
Now, when I fill in all the necessary data and try to persist it to database, I get an exception telling me that the insert into table WorkDay failed because the StoreID had null value and the table constraint doesn't allow nulls for that column (which is, of course, expected behavior).

I understand the reason for this exception, but I don't know how to solve it.
The reason why the insert fails is because the StoreID gets generated upon insert, but the WorkDay collection gets saved first, in the time when the StoreID hasn't yet been generated!

So, how do I force NHibernate to generate this ID to pass it to dependent tables? Or is there another solution for this?

Thank you!

Thanks you for the post.