Question About "Allow Null" In Attribute Table

[HMorrell]

Hello, 

I am trying to create fields in an Attribute Table that do not "Allow Null". This way we cannot accidently miss collecting a bit of data in the field. I was able to get some of the fields to not "Allow Null" but for some reason the fields "DBH", "Height", and "DULT #"  are all still allowed to be Null. Any advice on how to make these fields truly "Not Null"

I included a screen shot of the attributes table below to help.

Thank you!

[RobertBorchert · Accepted solution]

you may need to do a temporary calculation and make sure all entries for those fields has a value in it  before you try to change it. 

Meaning it may not allow you to set it to not allow null unless there are no nulls.  

[HMorrell]

Thanks! I appreciate your help. I just made a fake point and added some fake data. The three fields I listed are still allowed to be Null though.

[RobertBorchert]

You may need to start with an empty feature. Design your table and then add data to it.

Are those fields being used for symbols and or labels as well?

Is the feature participating in a Feature or Map service. You may need to stop the services that are using the feature class first.  

[HMorrell]

Hello again, thanks for continuing to ask questions. They will be used for symbols. Also, it is a feature. Thanks again!

[HMorrell]

Oh! It seems to have worked now that I have the layer on FieldMaps and am using it. Thank  you so much!