hello

I am trying to do a one to one relation between two tables.
The first one has an "assigned" generator for the <id> tag.
And the second a "foreign" generator.
Both tables shared the same primary key, in my case :Worder_extrulg

And the error is:
[code]Exception non g

After "resultat1.Lgextru=Lg1;"
Add "Lg1.Resultat = resultat1;"

thanks for your help!

but i have always the same error. :-(
I have used your advice in my program like this:




note: my configuration : Nhibernate 0.8.0.2 + Mysql 4.1.8 +VS 1.1 +connector .Net 1.0.4

As simple as it sounds, I think there is an error here:




there is an extra space between "cascade" and "="



this little error may be preventing the cascading of the property. Also, I would suggest enabling Log4net so you can see the SQL that is generated. That might give us a better clue.

-devon

Hello!

Good Morning

I have the same error: "Could not synchronise database state with session".
And MySql.Data.MySqlException :#23000Cannot add or update a child row.

is my problem comes from Mysql?
i attach at this post my Mysql's scripts:

Table Extrusion:



Table resultat:



Foreign key:


Thanks for your help!

Best regards,
Guillaume

I didn't notice that you used your "string" primary keys to create the <one-to-one> relationship. I am not sure if it can work (either because they are string or because primary keys cannot be used like this).

hi!

I have changed my generator to an native's generator with a int type.
i have the error: Could not save object : #23000Cannot add or update a child row... :(

i would like to unserstand what is the best way to realize a relation like this ("<one to one> with Mysql").
Mysql didn't like maybe the relation 1:1 with the share of the same primary key.
:?:


thanks for your help

Guillaume

It seems to me you have circular foreign key constraints in there :) leave only one of them, otherwise MySQL won't let you insert any row at all in the tables.

I haven't used MySQL in quite some time, however, I am currently using a PK-> PKFK relationship in MSSQL for polymorphic associations and it works fine. Also, I have in the past used "String" objects as the primary key / NHibernate id without problem-- again in MSSQL.

Have you tried to insert your data into the MySQL database using the isql app? That would uncover any problems you might have in your datamodel.

-devon

Hello everybody!

i have some questions for you.
I have used to realize my database the Merise's Model.
And in this model we can see that the relation 1:1 between two tables is made by the methods like this:

first one :

table A:

id_A (pK)
id_BFK)

table B:

id_B(PK)
id_A(FK)

the second :

table A:

id_A(PK,FK)

table B

id_A(PK,FK)

As NHibernate needs to use the same primary key between the two tables.
it's the reason why i have choosen the second method.
And i don't understand why i should use a polymorphic (in fact 1:n relation in Merise's Model) association to realize the one to one Nhibernate's relation.

I apply your advices and use the polymorphic association (PK--->PKfk),with the same Primary key on both tables.
But i have the same problem, could not synchronize database state with session.


Thank you very much for your help

have a good day :lol:

Guillaume

Thanks a lot!
:D
the relation <one to one > works fine with the PK-->PKFK relation. 8)
The problem is the position of the function Save.
We should save First, and Flush then.
But not at the end of the transaction.
could you explain that ?
Furthermore I have already teh same question.
Why i use in fact a 1:n relation in merise Model to realize in Nhibernate a 1:1 relation?

If you are an idea? :?:

Thank you very much kpixel,Sergey and DevonI!!!!!

My source if people is interested....


namespace Cablerie.Mapping
{
public class foreign
{

public foreign()
{

}
public void initialisation()
{

Configuration cfg = new Configuration();
cfg.AddAssembly("Cablerie");
ISessionFactory factory = cfg.BuildSessionFactory();
ISession session = factory.OpenSession();
ITransaction transaction = session.BeginTransaction();

try
{

LongueurExtrusion Lg1 = new LongueurExtrusion();
Lg1.Wextru = "BBBBBB/BB";
Lg1.NumeroBobine="BBBBBB32";
Lg1.PressionCaterpillar=12.58;
Lg1.TensionEnrouleurExterne=154.28;
Lg1.FeuillePrereglage="78-kl";
Lg1.BoiteVitesseCabestan=2500.50;
Lg1.BoiteVitesseDerouleur=150.24;
Lg1.BoiteVitesseEnrouleurMachine=458.12;
Lg1.Core="7-46ZV";
Lg1.DiametreExtrusionP1=11.4;
Lg1.DiametreExtrusionP2Chaud=6.25;
Lg1.DiametreExtrusionP2Froid=7.58;
//Save FIRST

session.Save(Lg1);

ExtrusionResults resultat1 = new ExtrusionResults();

resultat1.Lgextru=Lg1;
Lg1.Resultat=resultat1;
resultat1.MoyDtf10=14.58;

//Flush
session.Flush();
}
finally
{
transaction.Commit();
session.Close();
}

}
}
}