Hi,

I'm using a one-to-many relation between two tables in my application.

table 1 - Id numeric not null (primary key),
BName varchar(20),
IssuedTo numeric

table 2 - UId numeric not null(primary key),
UName varchar(25)

In my table1.hbm.xml -

<many-to-one name="Table2" class="MyAssembly.Table2, MyAssembly" column="UId"/>

and in table1.cs -

private Users user; //also having public property for this

In my table2.hbm.xml -

<set name="Table1">
<key column="IssuedTo"/>
<one-to-many class="MyAssembly.Table1, MyAssembly"/>
</set>

In my table2.cs -

private IDictionary tbl1; //also having public property for this

Now i'm able to save entries to table2 but while saving entry to Table1 i received the following exception

"Invalid mapping information specified for type Core.Users, check your mapping file for property type mismatches"

Inner exception - "Unable to cast object of type 'NHibernate.Collection.Set' to type 'System.Collections.IDictionary'."

Can anyone help me to correct my mistake in this?

Thanks and Regards,
Padmavathy T.

Use Iesi.Collections.ISet instead of IDictionary.

Hi,

Thanks for your reply.

After changing this as you have said, i received another exception at

Table1 tbl1 = (Table1)session.CreateCriteria(typeof(Table1)).Add(NHibernate.Expression.Expression.Eq("Id", id)).SetFetchMode("tbl1", FetchMode.Lazy).List()[0];

saying

"Unable to perform find"

InnerException - "ERROR: 42703: column this.uid does not exist"

Thanks and Regards,
Padmavathy T.

Here, column="IssuedTo" instead of column="UId", me thinks.

Gert

Hi,

Thanks you For your reply.

When i tried by changing column="uid" to column="IssuedTo" ,

<many-to-one name="Table2" class="MyAssembly.Table2, MyAssembly" column="IssuedTo"/>

i got

{"Repated column in mapping for class Core.Table1 should be mapped with insert=\"false\" update=\"false\": IssuedTo"} exception

So i tried in the following ways,

1.I commented the

'property name="IssuedTo" column="IssuedTo" type="int" '

which i gave earlier.

Now it worked well. I'm able to display the entries in the table but fails to insert the values into 'IssuedTo' column.

2. When i completely commented the "<many-to-one../>" mapping and left the <property.../> as it was before, this worked quite well but didnt fetch values for

Users user;//also public property exists

in table1.cs.

What have i done wrong again?

Thanks and Regards,
Padmavathy T.

Having a full mapping for both classes might be helpful... From what I have seen:
<many-to-one name="Table2" class="MyAssembly.Table2, MyAssembly" column="IssuedTo"/>

Telss that Table1 class must have property named Table2, with type MyAssembly.Table2

Also, I would write <set name="Table1" inverse="true"> in mapping for Table2

Gert

Hi,

My table1.hbm.xml contains,

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="MyAssembly.Table1, MyAssembly" table="Table1">
<id name="Id" column="Id" type="int">
<generator class="assigned"/>
</id>
<property name="BName" column="BName" type="string" length="20"/>
<property name="IssuedTo" column="IssuedTo" type="int"/>
<!--<many-to-one name="Table2" class="MyAssembly.Table2, MyAssembly" column="IssuedTo"/>-->
<set name="Table2" inverse="true">
<key column="IssuedTo"/>
<element type="int"/>
</set>
</class>
</hibernate-mapping>

and my table2.hbm.xml has

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="MyAssembly.Table2, MyAssembly" table="Table2">
<id name="UId" column="UId" type="int">
<generator class="assigned"/>
</id>
<property name="UName" column="UName" type="string" length="25"/>
<set name="Table1" cascade="none">
<key column="IssuedTo"/>
<one-to-many class="MyAssembly.Table1, MyAssembly"/>
</set>
</class>
</hibernate-mapping>


And in my cs file, i'm having

Table1 table1 = (Table1)session.CreateCriteria(typeof(Table1)).Add(NHibernate.Expression.Expression.Eq("Id", id)).SetFetchMode("Table2", FetchMode.Default).List()[0]; //where Table2 is the property.

On executing the application, i received that
"Cannot convert type 'Table2' to NHibernate.Collection.Set"
Then i changed
public Table2 Table2
{
}

to
public Set Table2
{
}

Now it says

"could not initialize collection: [MyAssembly.Table1.Table2#1]"

Thanks and Regards,
Padmavathy T.

Try

table1.hbm.xml

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="MyAssembly.Table1, MyAssembly" table="Table1">
<id name="Id" column="Id" type="int">
<generator class="assigned"/>
</id>
<property name="BName" column="BName" type="string" length="20"/>
<many-to-one name="IssuedTo" class="MyAssembly.Table2, MyAssembly" column="IssuedTo"/>
</class>
</hibernate-mapping>

table2.hbm.xml

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="MyAssembly.Table2, MyAssembly" table="Table2">
<id name="UId" column="UId" type="int">
<generator class="assigned"/>
</id>
<property name="UName" column="UName" type="string" length="25"/>
<set name="Table1" cascade="none" inverse="true">
<key column="IssuedTo"/>
<one-to-many class="MyAssembly.Table1, MyAssembly"/>
</set>
</class>
</hibernate-mapping>

Sorry, as You did have property

public Table2 Table2, then

<many-to-one name="Table2" class="MyAssembly.Table2, MyAssembly" column="IssuedTo"/>

Hi,

Its working well, thanks for your help. But still got one more issue.

When I tried to display the records in the table 'Table1' using 'createcriteria' method, it returns 'Issued To' as 0, always.

I changed the things in .hbm.xml files as you have mentioned.

Thanks and Regards,
Padmavathy T.

Well, as the IssoedTo property of Tbale1 class is mentioned in hbm map, it is transient.
If You really need IssuedTo int property in Table1, then You have couple of options. But in normal situation You should not deal with Id refrences at class level... as You have object references already.

1. as suggested earlier by NHibernate:


add a line to table1.xml.hbm:

<property name="IssuedTo" column="IssuedTo" type="int" insert="false" update="false" />

alternatively
2. Make the IssuedTo (or Table2) property calculated, with code:

public int IssuedTo
{
get { return this.Table2.UID; }
// set { this.Table2 = (table2)someSession.GetObject(typeof(table2), value); }
}

Hi,

Thank you so much. Its working now !!!

Thanks and Regards,
Padmavathy T.