This method allows loading a null value in an attribute, and enables independence from the Generate null for nullvalue() property used in assigning a null value attribute.
Objects: Procedure, Transaction, Web Panel
Java, Ruby (up to GeneXus X Evolution 3), RPG, Visual FoxPro (up to GeneXus X Evolution 3), Cobol
If the attribute allows nulls in the table, using this method can force the attribute to take the null value.
The SetNull method is applied as follows:
- Attributes: The attribute must accept nulls (Nullable property = Yes)
- Variables based on BC: The associated attribute must accept nulls (Nullable property = Yes)
- Variables based on SDT, for example, to stop recursion.
If you define an 'Employee' SDT with a 'Manager' member of the type 'Employee', to stop recursion you have to program &Person.Manager.SetNull().
Before referring to the manager, ask if &Employee.Manager.Isnull(). If you do not program this line, the Manager is automatically initiated.
&Employee.Id = 99
&Employee.Name = 'Mary Shelley'
&Employee.Manager.Id = 69
&Employee.Manager.Name = 'Er'
Programming is the same as in previous versions, plus IsNull() and SetNull() handling.
The result is the following:
OwnerCel.SetNull() if OwnerName.IsEmpty();
X = Y