I have inherited a table with two fields, one decimal, one string. These together represent the primary key. I need both fields on a maintenance form, bound to textboxes.

Display/Edit/Save is working. I cannot get a new record to add.

I get 'Conversion from type 'DBNull' to type 'String' is not valid.' on the line:

Return CType(Me.CurrentRow.Item("ITREPORT"), System.String) in the field properties. I tried to set the defaultValues and the first one sets fine, the second always gives the above error, regardless of the order set. I have PrimaryKeyIsAutoIncremented = False, PrimaryKeyIsUpdateable = True, and even tried out AllowNullsOnNewRow = True. The database fields (DB2) are set to not allow nulls, and have default values set.

I know this could be fixed easily by adding a proper autoincrement key column but I cant, the table is part of a legacy system and the customer is insistant it work as described above, frankly I'm not sure why it isnt. It works fine if the fields are unbound from the textboxes.

I must be missing somethign simple. Which is likely since I havent been coding much lately.

The solution will prevent the error, but is not the cause of the error.  You actually should not have to do this.  From what I understand, you are creating a new record.  At this point, the database type has no relavance as all of this is intrinsic to the BO.  So it would appear that when you are adding a record the fields are not being initialized...and/or you are referencing this field either through a manual binding, event, or some other code before it gets initialized.

By default, a BO has the AllowNullValuesONnewRow set to false, which forces all rows to be initialized with a default value when a new row is created.  So the NULL is not coming from there...it is happening in the Get of the strong-typed property which means that something is trying to call a GetValue before it is initialized.

You might check your mappings or place a breakpoint in the Get of the property to see what is pulling the value.  You have a "bandaid" on it so to speak and it would probably be a good idea to find the source of the issue.