NullReferenceException: I load Class from column holds NULL

treebhoph · **Joined:** Thu Jan 19, 2006 7:24 am **Posts:** 17

I use NHibernate 1.2.0 Beta1

"System.NullReferenceException: Object reference not set to an instance of an object"

I get this ERROR when i try to load Entity Class from a table's column contains NULL value, this column's type is MySql Varchar;
however if the colums has some value , the entity class can be loaded without ERROR!

How should i do for this problem?

sergey · **Posted:** Tue Oct 24, 2006 2:58 am

Create a simple test case (classes, mappings, code) and report it to JIRA.

fabiomaulo · **Joined:** Tue May 30, 2006 1:25 am **Posts:** 29

treebhoph wrote:

How should i do for this problem?

I think the problem is in your class.

Try this:

Mapping:

Code:

   <class name="A">
      <id name="Id" column="Id" type="Int32">
         <generator class="native"/>
      </id>
      <property name="Name"/>
   </class>

Class:

Code:

   public class A
   {
      private int _id;
      public int Id
      {   
         get { return _id; }
         set { _id = value; }
      }

      private string _name;
      public string Name
      {
         get { return _name; }
         set { _name = value; }
      }   
   }

Test:

Code:

         A a = new A();
         int savedId;
         using (ISession s = OpenSession())
         {
            s.Save(a);
            savedId = a.Id;
            s.Flush();
         }
         a = null;
         using (ISession s = OpenSession())
         {
            a= s.Load<A>(savedId);
            Assert.IsNull(a.Name);
         }         

The test work fine.

Please, after try it comment the NH-770 so we can close it.

Bye

P.S. Please, don't post JIRA more than one time.

treebhoph · **Joined:** Thu Jan 19, 2006 7:24 am **Posts:** 17

It still Error.. I just add Attached files contained class, mapping, code and a log file.

http://jira.nhibernate.org/browse/NH-772

The Error always arise when I try to load class form table's column contained Null, Column Type is Varchar

fabiomaulo · **Joined:** Tue May 30, 2006 1:25 am **Posts:** 29

treebhoph wrote:

It still Error.. I just add Attached files contained class, mapping, code and a log file.

http://jira.nhibernate.org/browse/NH-772

The Error always arise when I try to load class form table's column contained Null, Column Type is Varchar

Confirmed. The problem is in your class an not in NHb.
Next time please use this forum and post mapping and class implementation before create three JIRA.
Thanks.