Proper Delete Query in nHibernate

rooivalk · **Joined:** Tue Sep 21, 2010 9:09 am **Posts:** 2

hi everyone, im totally new to nhibernate.
currently im trying to use it in C# project.

but I ran across problem when I want to delete record.

here's my mapping for ItemUnit table

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
                   assembly="Testing"
                   namespace="Model">

  <class name="ItemUnit" table="ItemUnit">

    //This is how I setup the composite ID
    <composite-id>
      <key-many-to-one name="ItemDetail" class="Item" column="Item" lazy="false" />
      <key-many-to-one name="UnitDetail" class="Unit" column="Unit" lazy="false" />
    </composite-id>

    <property name="Coefisien"   column="Coefisien"  type="String"/>
    <property name="AuStatus"  column="AuStatus"  type="String"/>
    <property name="AuUser"  column="AuUser"  type="int"/>
    <property name="AuTime"  column="AuTime"  type="DateTime"/>

  </class>
</hibernate-mapping>

and here's my code:

Code:

            //This is code to get pre-coded ID from a combobox

            PairData pairItem = (PairData)cmbItem.SelectedItem;
            int itemKey = pairItem.key;

            // Setup nhibernate configuration

            Configuration config = new Configuration();
            config.AddAssembly(typeof(ItemUnit).Assembly);

            // Setup nhibernate session

            ISessionFactory factory = config.BuildSessionFactory();
            ISession session = factory.OpenSession();
            ITransaction transaction = session.BeginTransaction();

            IQuery query = session.CreateQuery("SELECT a FROM ItemUnit a WHERE a.ItemDetail = " + itemKey);            
            IList<ItemUnit> itemunit = query.List<ItemUnit>();

            session.Delete(itemunit);

i got error message "Unknown entity class: System.Collections.Generic.List`1[[Model.ItemUnit, Testing, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"

when I tried to change the code like this:

Code:

            //This is code to get pre-coded ID from a combobox

            PairData pairItem = (PairData)cmbItem.SelectedItem;
            int itemKey = pairItem.key;

            // Setup nhibernate configuration

            Configuration config = new Configuration();
            config.AddAssembly(typeof(ItemUnit).Assembly);

            // Setup nhibernate session

            ISessionFactory factory = config.BuildSessionFactory();
            ISession session = factory.OpenSession();
            ITransaction transaction = session.BeginTransaction();

            Object result = session.CreateSQLQuery("DELETE from ItemUnit");
            session.Delete(result);

I got error message "Unknown entity class: NHibernate.Impl.SqlQueryImpl". FYI i have already using NHibernate.Impl.

so, how to do it properly?

thx :)

wolli · **Posted:** Wed Sep 22, 2010 1:46 am

Is your mapping files marked as "Embedded Resource" ?

rooivalk · **Joined:** Tue Sep 21, 2010 9:09 am **Posts:** 2

[quote=wolli]Is your mapping files marked as "Embedded Resource" ?[/quote]

thx for ur reply, yes.

btw, I succeded using this CreateSQLQuery:

Code:

    Object result = session.CreateSQLQuery("DELETE from ItemUnit where item = :itm")
                                .AddScalar("count", NHibernateUtil.Int32)
                                .SetParameter("itm", itemKey)
                                .UniqueResult();

so, my delete problem, less or more, is solved.
although I still want to know how to delete using CreateQuery.

wolli · **Posted:** Wed Sep 22, 2010 2:30 am

Ah, sorry, should've read your code more carefully. session.Delete doesn't accept lists. This should work:

IQuery query = session.CreateQuery("SELECT a FROM ItemUnit a WHERE a.ItemDetail = " + itemKey);
IList<ItemUnit> itemunit = query.List<ItemUnit>();

foreach( ItermUnit iu in itemunit)
session.Delete(iu);

CreateQuery can only be used for select.