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| Delete Field myfield vs SET myfield = NULL |
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| mrT |
 Posted: Tue Oct 23, 2007 4:48 am Post subject: Delete Field myfield vs SET myfield = NULL |
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Newbie
Joined: 23 Oct 2007
Posts: 1
Location: Stockholm
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Hi!
I found a major issue with the difference of deleting a field and setting it to NULL.
I'm building up an OutputRoot.MRM and in some conditions I need to delete parts of the OutputRoot.MRM structure. So I used the DELETE FIELD function. I propagate the flow, sends it through a RCD and then to output node.
Later in the flow I build up a new OutputRoot.MRM which I want to send through another RCD and then to output node. During my creation of the MRM the flow freezes completely. The message is stuck and no other can be processed. I have to delete the process to be able to use the flow again.
If I instead build up my second MRM in the Environment tree it all looks good there but when I copy it into OutputRoot.MRM DOMAIN 'MRM' the result is that my last tags replaces the MRM. Like this:
Properties
MQMD
tag9
tag10
tag11
tag12
If I step through my copying I can see that the OutputRoot.MRM is building up until it reaches tag9.
If I don't use DOMAIN 'MRM' the structure looks good in OutputRoot.MRM until it reaches the RCD, it then throws exception that my first tag is missing.
When I change the line in the first creation of OutputRoot.MRM to
DELETE FIELD myfield
to
SET myfield = NULL
the second creation of the OutputRoot.MRM works perfectly well.
So my question is: What is the difference of using DELETE function and setting a field to NULL?? |
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| Gaya3 |
| Posted: Tue Oct 23, 2007 5:41 am Post subject: |
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Jedi
Joined: 12 Sep 2006
Posts: 2493
Location: Boston, US
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HI
After deleting the field did you re-create it for the future use, if not, it will throw an exception.
if you use null, i dont think its required to re-create the field again
Regards
Gayathri
_________________
Regards
Gayathri
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Do Something Before you Die |
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| JLRowe |
| Posted: Tue Oct 23, 2007 5:56 am Post subject: Re: Delete Field myfield vs SET myfield = NULL |
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Yatiri
Joined: 25 May 2002
Posts: 664
Location: South East London
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| mrT wrote: |
| So my question is: What is the difference of using DELETE function and setting a field to NULL?? |
A field can still be present and have a NULL value, there is a difference between a field being not present (i.e. deleted) and being present but having a NULL value.
NULL means undefined/unknown. |
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| jefflowrey |
| Posted: Tue Oct 23, 2007 6:02 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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You have to be very careful when you build anything in the Environment, that you make sure that it's got the proper parser associated with it.
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I am *not* the model of the modern major general. |
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