topic A <Null> Coded Value? in ArcObjects SDK Questions

A <Null> Coded Value?

GregRieck — Wed, 17 Aug 2011 13:44:46 GMT

Hello,

I'm looking for some help in setting a value to <Null>. I have a field in a table of type Long and it is a coded value domain. In ArcMap I am able to assign a value of <Null> to the field and save it without error. I'd like to be able to do this programmatically.

How do I assign a <Null> to a Long data type in code?

  row.set_Value(FIELD INDEX, WHAT GOES HERE?);
  cur.UpdateRow(row);

Re: A Coded Value?

JamesCrandall — Sat, 11 Dec 2021 06:59:49 GMT

Just a quick shot, but have you tried Nullable(Of Integer)? The problem is that in VB, Integers cannot be null (at least that's what I believe). Setting your Integer variable to "Nothing" would only produce the default value of 0(zero). But the Integer? Type should get you the result you want.

Try something like this:

  Dim myIntValue As Integer? = Nothing
  row.set_Value(FIELD INDEX, myIntValue);
  cur.UpdateRow(row);

Hello,

I'm looking for some help in setting a value to <Null>. I have a field in a table of type Long and it is a coded value domain. In ArcMap I am able to assign a value of <Null> to the field and save it without error. I'd like to be able to do this programmatically.

How do I assign a <Null> to a Long data type in code?
  row.set_Value(FIELD INDEX, WHAT GOES HERE?);
  cur.UpdateRow(row);
G

Re: A Coded Value?

GregRieck — Wed, 17 Aug 2011 15:04:11 GMT

Hi James,

Thanks for the response. Yes, I have tried all sorts of Nullable type implementations and they have not worked. I find it odd that a Coded Value Domain always presents with a "<Null>" option and allows you to assign it. Also, I do not have any defined coded value of "Null" and it still allows me to update the field to Null in ArcMap. So, I'm assuming there has to be a way to accomplish this in code, correct?

Some Examples...
Int? num = null;

Long? num = null;

Bool? b =null;
Object obj = b;

Re: A Coded Value?

GregRieck — Sat, 11 Dec 2021 06:59:52 GMT

I figured this out!

Turns out it had nothing to do with NULL. The problem was that the cursor was initialized as a SEARCH cursor but being used as an UPDATE cursor.

WRONG:

ICursor cur = Tab.Search(queryfilter, false);
row.set_Value(FIELD INDEX, WHAT GOES HERE?);   
cur.UpdateRow(row);

CORRECT:

ICursor cur = Tab.Update(queryfilter, false);
row.set_Value(FIELD INDEX, DBNull.Value);   
cur.UpdateRow(row);

Re: A Coded Value?

MichaelHoward1 — Thu, 08 Sep 2011 18:09:08 GMT

Does anyone know how to accomplish this in Java?

I have tried null, "Null", etc. It seems that Java does not have a System.DBNull.Value like C# does.

How can I set the value of a field to null in my code?

Re: A Coded Value?

DubravkoAntonic — Thu, 08 Sep 2011 20:28:04 GMT

I'm not Java but google is 🙂
http://bleu.west.spy.net/~dustin/spyjar/doc/2/net/spy/db/DBNull.html

does it help?

topic A &lt;Null&gt; Coded Value? in ArcObjects SDK Questions

A <Null> Coded Value?

Re: A Coded Value?

Re: A Coded Value?

Re: A Coded Value?

Re: A Coded Value?

Re: A Coded Value?

topic A <Null> Coded Value? in ArcObjects SDK Questions