I have the following fluent mapping set up for an entity:
*Id(x => x.Id);
References(x => x.UserNominee).UniqueKey("UQ_SurveyNominee");
References(x => x.SurveyRequest).UniqueKey("UQ_SurveyNominee");
Map(x => x.NominationDate).Not.Nullable();*
Unfortunately the unique index is only created on one of the columns on the resulting SQL Server table and not both of them as I expected. What am I doing wrong?
Regards
mjj
OK I have managed to get this to work but I am not sure why it should make any difference. I had to change the mapping on the parent "SurveyRequest" entity. I changed the mapping from:
HasMany(x => x.SurveyAwarenessNominees)
.KeyColumn("SurveyRequest_Id")
.LazyLoad()
.Inverse()
;
to
HasMany(x => x.SurveyAwarenessNominees).Cascade.All().Inverse();
My unique index is now correctly created on the two foreign key columns.
Related
How do I create a one to many mapping which has a bridge table in the middle?
I basically have 3 tables: Items, Tags, and TagsToItems.
Each Item can have many Tags as defined by the TagsToItems table. How do I set up this mapping correctly using Fluent NHibernate?
I've been playing with HasMany but haven't quite figured out how this works with a bridge table.
HasMany(x => x.Tags).Table("TagsToItems").KeyColumn("ItemId");
My latest attempt to solve this problem looks like this:
HasManyToMany(x => x.Tags)
.AsBag()
.Table("TagsToItems")
.ParentKeyColumn("ItemId")
.ChildKeyColumn("TagId")
.Cascade.All()
.Inverse();
However this is throwing the error:
Initializing[Namespace.Item#11]-failed to lazily initialize a
collection of role:
Namespace.DataAccess.NHibernate.Entities.Item.Tags, no session or
session was closed
It turns out that the problem is with using the Tags collection associated to an Item.
The Tags collection could not be lazily initialised because by the time I was trying to use it (in my view) the session scope of the NHibernate session had closed.
I solved this by setting .Not.LazyLoad() on the mapping:
HasManyToMany(x => x.Tags)
.AsBag()
.Table("TagsToItems")
.ParentKeyColumn("ItemId")
.ChildKeyColumn("TagId")
.Not.LazyLoad()
.Cascade.All();
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 [b]WorkDay[/b] 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!
Here's the code for StoreMap
public class StoreMap : ClassMap<Store> {
public StoreMap() {
Id(x => x.StoreID)
.GeneratedBy.GuidComb();
Map(x => x.City);
Map(x => x.Description);
Map(x => x.Email);
Map(x => x.Fax);
Map(x => x.ImageData).CustomType("BinaryBlob");
Map(x => x.ImageMimeType);
Map(x => x.Name);
Map(x => x.Phone);
Map(x => x.Street);
Map(x => x.Zip);
HasMany(x => x.WorkDays)
.Inverse().KeyColumn("StoreID").ForeignKeyCascadeOnDelete()
.Cascade.All();
}
}
and this is for the WorkDayMap
public class WorkDayMap : ClassMap<WorkDay>{
public WorkDayMap() {
Id(x => x.WorkDayID)
.GeneratedBy.Identity();
Map(x => x.TimeOpen);
Map(x => x.TimeClose);
References(x => x.Store).Column("StoreID");
References(x => x.Day).Column("DayID");
}
}
NHibernate shouldn't insert the WorkDay first, so there must be an error in your code. Make sure you do all of the following:
Add all WorkDay objects to the WorkDays collection.
Set the Store property on all WorkDay objects to the parent object.
Call session.Save() for the Store but not for the WorkDay objects.
edit: You should also note that ForeignKeyCascadeOnDelete() won't change anything at runtime. This is just an attribute for the hbm2ddl tool. If you want NHibernate to delete removed entries, use Cascade.AllDeleteOrphan().
It probably inserts the Workday before the Store because the first has an identity generator. This forces NH to execute an INSERT statement to generate the ID. guid.comb is generated in memory, NH doesn't need the database.
NH tries to access the db at the latest possible point in time, to avoid unnecessary updates and to make use of batches. Workday is inserted when you call session.Save, Store is inserted when it flushes the session next time (eg. on commit).
You shouldn't use the identity generator (unless you are forced to use it). It is bad for performance anyway.
If it still doesn't work, you probably need to remove the not-null constraint on the foreign key. NH can't resolve it every time. There is some smart algorithm which is also able to cope with recursive references. But there are sometimes cases where it sets a foreign key to null and updates it later even if there would be a solution to avoid it.
I know that I can Map(x => x.GroupName).WithUniqueConstraint() for a single property.
But how do create a composite unique constraint in fluent nHibernate (where the unique constraint operates on the combination of two columns)?
In the latest version that I have used, it isUniqueKey("KeyName")that does this.
Map(x => x.Something).UniqueKey("KeyName");
Map(x => x.SomeOtherThing).UniqueKey("KeyName");
Use SetAttribute in your mapping file like so:
Map(x => x.Something).SetAttribute("unique-key", "someKey");
Map(x => x.SomeOtherThing).SetAttribute("unique-key", "someKey");
I have a one to many relationship with the following config
HasMany(x => x.Staff)
.Inverse()
.Cascade.All();
But I get a collection failed to initialize error.
Dont I have to specify the foreignkey here, examples I found do not????
How does it know which is the foreign key?
EDIT: Looking closer at the exception the sql is trying to use field Staff_id
when I have said it is StaffID??
Malcolm
Try
HasMany(x => x.Staff)
.KeyColumnNames.Add("StaffID")
.Inverse()
.Cascade.All();
Staff_id is the auto configure default, although you can set what conventions auto-configure uses.
If you're mapping the collection to an IList<T>, you'll want to add AsBag() or NHibernate will complain about a missing "idx" column. If you want to lazy load the collection add .LazyLoad(). And I usually go with .Cascade.AllDeleteOrphan().
I have this table mapping (details don't really matter I think):
WithTable("COPACKER_FACILITY");
Id(x => x.FacilityNumber, "FACILITY_NUM").GeneratedBy.Sequence("FACSEQ");
Map(x => x.FacilityName, "FACILITY_NAME").Not.Nullable().Trimmed();
Map(x => x.AddressLine1, "ADDR1").Not.Nullable().Trimmed();
...
WithTable("FACIL_OTH_AUDIT_INFO", m =>
{
m.WithKeyColumn("FACILITY_NUM");
m.Map(x => x.ProdnShiftsNum, "PRODN_SHIFTS_NUM").Not.Nullable();
m.Map(x => x.ProdnCapacity, "PRODN_CAPACITY").Not.Nullable();
m.Map(x => x.ProdnLinesNum, "PRODN_LINES_NUM").Not.Nullable();
m.Map(x => x.AuditScore, "AUDIT_SCORE");
m.References(x => x.FacilStatus, "STATUS_IND").Not.Nullable();
});
HasMany(x => x.ComplianceFlags)
.KeyColumnNames.Add("FACILITY_NUM")
.Inverse()
.Cascade.All();
...
The reason for the one to one table is for audit reasons. There's a FACIL_OTH_AUDIT_INFO_HIST table that should get a record for every insert and update in the main table.
My question: How can I know when an insert or update happens in that table so I know to insert an audit record?
Many thanks!
+1 to what kvalcanti said... here's another post that I think explains it a little better though (and shows you how to do it without XML configuration!). I'm doing what this guy is doing on my project and it's working really well.
http://www.codinginstinct.com/2008/04/nhibernate-20-events-and-listeners.html
Caveat: I'm not inserting new objects that need to be saved in this event in my project, which I assume will not be a problem, but I can't say for sure since I'm not doing exactly what you're doing.
I posted the final solution to this problem and thought I'd share
http://robtennyson.us/post/2009/08/23/NHibernate-Interceptors.aspx
You can use event listeners.
try http://nhibernate.info/doc/howto/various/creating-an-audit-log-using-nhibernate-events.html