null problem

[sed10]

Hi,
I put reals in a table as a sum from another table but I don't want to have null as solution. The process is heavy and I don't want to test all the datas. I tried to unauthorize null in the cases, but I lost lines in my table if I do like that.
Is there any solutions (perhaps a batch?)
Thanks

 

[syntax18]

U can set a default value for this field..

 

[sed10]

It's what I have done, but when I get a Null as solution of my sum, the 0 is replaced by this *$$$!!!§§ null...